message: Assert against proper exit code
diff: @@ -1042,6 +1042,7 @@ mod tests {
  ));
  // Block from the future version should result in generating JoinerEvent::Shutdown
  + // with proper exit code.
  let result_block_from_future: Result<BlockHeader, LinearChainSyncError> = Err(
  LinearChainSyncError::RetrievedBlockHeaderFromFutureVersion {
  current_version: protocol_version,
  @@ -1049,7 +1050,10 @@ mod tests {
  },
  );
  let joiner_event = generate_joiner_event(result_block_from_future, effect_builder).await;
  - assert!(matches!(joiner_event, Some(JoinerEvent::Shutdown(_))));
  + assert!(matches!(
  + joiner_event,
  + Some(JoinerEvent::Shutdown(ExitCode::Success))
  + ));
  // CurrentBlockHeaderHasOldVersion response should no longer generate JoinerEvent::Shutdown,
  // but None. See: https://github.com/casper-network/casper-node/issues/2338
  