Fix rare exception during shutdown in airtime_analyzer

python_apps/airtime_analyzer/airtime_analyzer/message_listener.py

@@ -120,7 +120,12 @@ class MessageListener:
 
     def disconnect_from_messaging_server(self):
         '''Stop consuming RabbitMQ messages and disconnect'''
+        # If you try to close a connection that's already closed, you're going to have a bad time.
+        # We're breaking EAFP because this can be called multiple times depending on exception
+        # handling flow here.
+        if not self._channel.is_closed and not self._channel.is_closing:
             self._channel.stop_consuming()
+        if not self._connection.is_closed and not self._connection.is_closing:
             self._connection.close()
    
     def graceful_shutdown(self, signum, frame):