small refactorings

components/shared/message_broker_wrapper.py

@@ -56,7 +56,7 @@ class MBWrapper:
         if type(message) is not bytes:
             message = str(message).encode()
         self._channel.basic_publish(exchange=self.exchange_name, routing_key='', body=message)
-        self.print(" [x] Sent %r" % message)
+        self.print("[{}] Sent {}".format(self.exchange_name, message))
 
     def close(self):
         self._connection.close()