updated shard id type to u32

neps/nep-0539.md

@@ -83,7 +83,7 @@ ShardChunkHeaderInnerV3 {
 Where alternatives for congestion info are decribed in more detail below in the 
 `Efficiently computing the congestion information` section. 
 
-Depending on the alternative solution this adds between 9 and 48 bytes to the
+Depending on the alternative solution this adds between 5 and 48 bytes to the
 chunk header, increasing it from 374 bytes up to 422 bytes in borsh representation.
 (Assuming no validator proposals included.) This in turn increases the block size
 by up to 48 bytes per shard.
@@ -173,7 +173,7 @@ The new chunk execution then follows this order.
     delayed_receipts_gas: u128,
     buffered_receipts_gas: u128,
     receipt_bytes: u64,
-    allowed_shard: u64`,
+    allowed_shard: u32`,
    }
    ```
 2. (new) Compute bandwidth limits to other shards based on the congestion information.
@@ -395,7 +395,7 @@ information needed by other shards.
 
 ```rust
 pub struct CongestionInfo {
-  allowed_shard: u64,
+  allowed_shard: u32,
   congestion_level: u8,
 }
 ```
@@ -425,7 +425,7 @@ pub struct CongestionInfo {
   delayed_receipts_gas: u128,
   buffered_receipts_gas: u128,
   receipt_bytes: u64,
-  allowed_shard: u64,
+  allowed_shard: u32,
 }
 ```