add log

pkg/ruleEngine/nodes/mqtt_broker_node.go

@@ -88,6 +88,7 @@ func (M *MQTTBrokerNode) Init(ctx ruleEngine.Context, config string) error {
 	M.mqttClient = c
 	go func() {
 		if token := c.Connect(); token.Wait() && token.Error() != nil {
+			fmt.Println(token.Error().Error())
 			return
 		}
 	}()