message: Delete previous QueueManager instance if creating multiple.
diff: @@ -51,6 +51,8 @@ QueueManager* QueueManager::instance() {
  void QueueManager::CreateInstance(MultiQueueWaiter* querydb_waiter,
  MultiQueueWaiter* indexer_waiter,
  MultiQueueWaiter* stdout_waiter) {
  + if (instance_)
  + delete instance_;
  instance_ = new QueueManager(querydb_waiter, indexer_waiter, stdout_waiter);
  }
  