message: Exit early for an empty vChecks in CCheckQueue::Add
diff: @@ -167,6 +167,10 @@ public:
  //! Add a batch of checks to the queue
  void Add(std::vector<T>& vChecks)
  {
  + if (vChecks.empty()) {
  + return;
  + }
  +
  {
  LOCK(m_mutex);
  for (T& check : vChecks) {
  @@ -176,11 +180,12 @@ public:
  nTodo += vChecks.size();
  }
  - if (vChecks.size() == 1)
  + if (vChecks.size() == 1) {
  m_worker_cv.notify_one();
  - else if (vChecks.size() > 1)
  + } else {
  m_worker_cv.notify_all();
  }
  + }
  //! Stop all of the worker threads.
  void StopWorkerThreads()
  