fix: Add check len msgs when process proposal (#1437)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Bug Fixes**
- Improved transaction message processing by ensuring at exactly one
message is present before unwrapping the payload.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

cosmos/runtime/chain/abci.go

@@ -51,10 +51,12 @@ func (wbc *WrappedBlockchain) ProcessProposal(
  continue
  }
 
- protoEnvelope := sdkTx.GetMsgs()[0]
- if env, ok := protoEnvelope.(*evmtypes.WrappedPayloadEnvelope); ok {
- envelope = env.UnwrapPayload()
- break
+ if len(sdkTx.GetMsgs()) == 1 {
+ protoEnvelope := sdkTx.GetMsgs()[0]
+ if env, ok := protoEnvelope.(*evmtypes.WrappedPayloadEnvelope); ok {
+ envelope = env.UnwrapPayload()
+ break
+ }
  }
  }