PYTHON-1050 Rare RuntimeError during shutdown.

Author: ajdavis

pymongo/periodic_executor.py

@@ -79,8 +79,8 @@ def join(self, timeout=None):
  if self._thread is not None:
  try:
  self._thread.join(timeout)
- except ReferenceError:
- # Thread already terminated.
+ except (ReferenceError, RuntimeError):
+ # Thread already terminated, or not yet started.
  pass
 
  def wake(self):