Fix nil interface conversion error

[yzang2019]

Describe your changes and provide context

This patch fix an edge case where the to be removed node doesn't exist, the interface conversion will fail with nil errors.

Testing performed to validate your change

Fixed this error:

Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: panic: interface conversion: interface is nil, not cache.Node
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: goroutine 2164 [running]:
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/iavl/cache.(*lruCache).remove(0xc00075df20, 0xc00064d080?)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/cache/cache.go:107 +0xb0
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/iavl/cache.(*lruCache).Add(0xc00075df20, {0x2d5e860, 0xc01c6762d0})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/cache/cache.go:77 +0x31b
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/sei-protocol/sei-db/sc/memiavl.(*Tree).addToCache(0xc00029f8b0, {0xc015e78f48, 0x16, 0x18}, {0xc00e648820, 0x184, 0x1a0})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/sc/memiavl/tree.go:309 +0x125
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/sei-protocol/sei-db/sc/memiavl.(*Tree).Get(0x213b780?, {0xc015e78f48, 0x16, 0x18})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/sc/memiavl/tree.go:225 +0x8e
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/storev2/commitment.(*Store).Get(0xc017035620?, {0xc015e78f48?, 0xc00905c400?, 0x1?})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/storev2/commitment/store.go:97 +0x26
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/store/cachekv.(*Store).getFromCache(0xc0208e9110, {0xc015e78f48, 0x16, 0x18})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/store/cachekv/store.go:72 +0x98
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/store/cachekv.(*Store).Get(0xc017035b90?, {0xc015e78f48?, 0x235083a?, 0x18?})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/store/cachekv/store.go:78 +0x25
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/store/gaskv.(*Store).Get(0xc0189e2660, {0xc015e78f48, 0x16, 0x18})
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/store/gaskv/store.go:43 +0x71
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/x/staking/keeper.Keeper.GetValidator({{0x2d65868, 0xc0001deb00}, {0x2d8f040, 0xc0004e4330}, {0x2d82fe0, 0xc0004cda40}, {0x7fedd3e92c98, 0xc000325520}, {0x2d8ea18, 0xc00075ccf0}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/x/staking/keeper/validator.go:17 +0x10a
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/x/staking/keeper.Keeper.mustGetValidator({{0x2d65868, 0xc0001deb00}, {0x2d8f040, 0xc0004e4330}, {0x2d82fe0, 0xc0004cda40}, {0x7fedd3e92c98, 0xc000325520}, {0x2d8ea18, 0xc00075ccf0}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/x/staking/keeper/validator.go:27 +0xe5
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/x/staking/keeper.Keeper.ApplyAndReturnValidatorSetUpdates({{0x2d65868, 0xc0001deb00}, {0x2d8f040, 0xc0004e4330}, {0x2d82fe0, 0xc0004cda40}, {0x7fedd3e92c98, 0xc000325520}, {0x2d8ea18, 0xc00075ccf0}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/x/staking/keeper/val_state_change.go:131 +0x4b8
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/x/staking/keeper.Keeper.BlockValidatorUpdates({{0x2d65868, 0xc0001deb00}, {0x2d8f040, 0xc0004e4330}, {0x2d82fe0, 0xc0004cda40}, {0x7fedd3e92c98, 0xc000325520}, {0x2d8ea18, 0xc00075ccf0}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/x/staking/keeper/val_state_change.go:27 +0x7b
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/x/staking.EndBlocker({{0x2d7e7d8, 0xc012bbaae0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, {0x11268b7c, ...}, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/x/staking/abci.go:25 +0xfb
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/x/staking.AppModule.EndBlock(...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/x/staking/module.go:174
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/types/module.(*Manager).EndBlock(_, {{0x2d7e7d8, 0xc012bbaae0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/types/module/module.go:550 +0x390
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/sei-protocol/sei-chain/app.(*App).EndBlocker(_, {{0x2d7e7d8, 0xc012bbaae0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /home/ubuntu/sei-chain/app/app.go:944 +0x79
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/baseapp.(*BaseApp).EndBlock(_, {{0x2d7e7d8, 0xc012bbaae0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/baseapp/abci.go:183 +0x149
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/sei-protocol/sei-chain/app.(*App).EndBlock(_, {{0x2d7e7d8, 0xc012bbaae0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /home/ubuntu/sei-chain/app/abci.go:32 +0x145
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/sei-protocol/sei-chain/app.(*App).ProcessBlock(_, {{0x2d7e7d8, 0xc012bbaae0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /home/ubuntu/sei-chain/app/app.go:1365 +0xb65
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/sei-protocol/sei-chain/app.(*App).FinalizeBlocker(_, {{0x2d7e7d8, 0xc012bbaab0}, {0x2d95358, 0xc0105b9a80}, {{0x0, 0x0}, {0x7ffe034eeed5, 0xa}, 0x37df884, ...}, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /home/ubuntu/sei-chain/app/app.go:1035 +0x335
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/cosmos/cosmos-sdk/baseapp.(*BaseApp).FinalizeBlock(0xc0001c8780, {0x2d7e730?, 0xc0004ca4c0?}, 0xc02446cb60)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/baseapp/abci.go:1081 +0x785
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/tendermint/tendermint/internal/proxy.(*proxyClient).FinalizeBlock(0xc000472620, {0x2d7e730, 0xc0004ca4c0}, 0x11?)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/internal/proxy/client.go:154 +0x102
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/tendermint/tendermint/internal/state.(*BlockExecutor).ApplyBlock(_, {_, _}, {{{0xb, 0x0}, {0xc00872ef90, 0x11}}, {0xc00a32cbe0, 0xa}, 0x1, ...}, ...)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/internal/state/execution.go:249 +0x987
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: github.com/tendermint/tendermint/internal/blocksync.(*Reactor).poolRoutine(0xc0042222c0, {0x2d7e730?, 0xc0004ca4c0}, 0x0, 0xc00a069fb0?)
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/internal/blocksync/reactor.go:698 +0x1595
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]: created by github.com/tendermint/tendermint/internal/blocksync.(*Reactor).OnStart
Jan 02 20:57:16 ip-172-31-24-248 seid[28083]:         /root/go/pkg/mod/github.com/sei-protocol/[email protected]/internal/blocksync/reactor.go:181 +0x64a