fix(lightclient): don't expect signer

[danwt]

Solves arts testnet issue

Nov 11 15:09:41 ip-10-0-2-46 rollapp-evm[12691]: time="2024-11-11T15:09:41Z" level=error msg="Submit batch[startHeight 776661 endHeight 0x2aee4e0 error broadcast tx: rpc error: code = Unknown desc = rpc error: code = Unknown desc = failed to execute message; message index: 0: hook: after update state: validate optimistic: got cons state but no signer addr: client: 07-tendermint-44: h: 776660: internal [cosmossdk.io/[email protected]/errors.go:155] With gas wanted: '18446744073709551615' and gas used: '443375' : unknown request]" module=settlement_client

We shouldn't expect light client signers for consensus states from pre upgrade rollapps.

This PR just makes the file the same as it is in #1354, which also fixes the problem because there is no automatic forking there, and the signer isn't looked up