Clear reserved_requests on connection loss. Closes #1325

celery/worker/consumer.py

@@ -736,6 +736,7 @@ class Consumer(object):
         # to the current channel.
         self.ready_queue.clear()
         self.timer.clear()
+        state.reserved_requests.clear()
 
         # Re-establish the broker connection and setup the task consumer.
         self.connection = self._open_connection()