This removes the special case in the processor. The initial guardian set
is now treated like a regular guardian set update, and the devnet
update check is executed on every update.
Fixes an edge case where processing a guardian set update would fail
with a spurious `abi: attempting to unmarshall an empty string while arguments are expected`
error, leaving the node in a bad state since restarting ethwatch
wouldn't cause the guardian set to be re-fetched.
ghstack-source-id: e580a65e90
Pull Request resolved: https://github.com/certusone/wormhole/pull/46