substrate fails to decode grandpa gossip message

## Describe the bug

- This occurred when I was running 2 gossamer nodes with one substrate node
- I occurred only once in substrate logs while i waited for some 110 blocks

```
2022-08-10 18:50:34.516 DEBUG tokio-runtime-worker afg: Error decoding message: Could not decode `GossipMessage::Commit.0`:
Could not decode `FullCommitMessage::message`:
Could not decode `CompactCommit::precommits`:
Could not decode `Precommit::target_hash`:
Not enough data to fill buffer
```