update nm is conn failed handler

nm/start.go

@@ -161,6 +161,7 @@ func monitorWorker(op *operate.DockerOp) {
 						if nodeManager.Status {
 							nodeManager.UpdateStatus(false)
 						}
+						log.Error("Received nm msg failed:%s", err)
 						return
 					}
 					if err != nil {