message: Don't report empty operations update to baker
diff: @@ -201,6 +201,9 @@ where
  ))
  .chain(MonitoredOperation::collect_errored(outdated, ops, &prot))
  .collect::<Vec<_>>();
  + if resp.is_empty() {
  + return;
  + }
  if let Ok(json) = serde_json::to_value(resp) {
  store
  .service()
  @@ -415,7 +418,6 @@ where
  .chain(MonitoredOperation::collect_errored(outdated, ops, &prot))
  .collect::<Vec<_>>();
  if let Ok(json) = serde_json::to_value(&resp) {
  - slog::trace!(&store.state().log, "============\n{:#?}", resp);
  store.service().rpc().respond_stream(act.rpc_id, Some(json));
  }
  }
  