Bugfix: Nissan LEAF, move battery-allows-closing writing

[dalathegreat]

What

This PR moves the battery_allows_contactor_closing writing for Nissan LEAF

Why

Periodic BMS reset would always cause this red X on the webserver, confusing users

It also confused users, some packs never set this bit as stated in the LEAF wiki

NOTE: with some Leaf BMS (so far only noticed on the 30kWh 2016) the line batteryAllowsContactorClosing = true is never set:

Battery-Emulator/Software/src/battery/NISSAN-LEAF-BATTERY.cpp

Line 745 in d759946

datalayer.system.status.battery_allows_contactor_closing = false;

. This prevents the automatic contactor sequence. A workaround is to force the value to always true. So if you are having problems with the contactor sequence, change the above line to datalayer.system.status.battery_allows_contactor_closing = true;

How

Instead of dynamically writing it based on CAN, always allow contactor closing on boot

This also makes the workaround no longer required

[mvgalen]

I understand that the old situation is not ideal, but the always allowing the contactors to close (even when BMS is being reset) seems a bit strange to me.
Shouldn't at least some sanity checks be done before enabling battery_allows_contactor_closing? Like, BMS powered and no faults present?

[dalathegreat]

Very good point @mvgalen , I changed this in commit 850922b , so now we need to get CAN from battery before we allow closing to happen!

Contactors can be on during the reset. We just allow 0W while resetting. If the BMS would not wake up, we open contactors after 60 seconds.

[mvgalen]

Yes, that is better. But are there no sanity checks we could do, like checking soc?