Add trace in case of execption was raised in rpc

pikatasks/__init__.py

@@ -104,6 +104,7 @@ def rpc(_task_name, **kwargs):
             channel.start_consuming()
             channel.close()  # after stopped consuming by either of the callbacks
     except Exception as e:
+        logger.error(traceback.format_exc())
         logger.error("{}: {}".format(e.__class__.__name__, str(e)))
         exception = RPCMessageQueueError(e)
     # done, return the result or indicate a problem