Investigate the why the vars nonce was wrong on part of the fleet.

[evanmcc]

Everything that loaded the rescue block manually seems to have had the wrong vars nonce, but gateways and other nodes that loaded a snap containing the rescue block halted because their nonce was wrong. Probably just not running all the hooks correctly post block save.

[xandkar]

@evanmcc Until full investigation of what exactly goes wrong in the presence of rescue blocks, we discussed a workaround with @Vagabond - just avoid making snaps with rescue blocks: https://github.com/helium/blockchain-core/pull/1195