message: Remove incorrect signatures in `register_block`
diff: @@ -143,7 +143,9 @@ impl BlockAcceptor {
  });
  }
  - // TODO: Remove any finality signatures with the wrong era.
  + // todo!() - return the senders of the invalid signatures.
  + self.signatures
  + .retain(|_, signature| signature.era_id == block.header().era_id());
  if let Err(error) = block.validate(&EmptyValidationMetadata) {
  warn!(%error, "received invalid block");
  