add default group

operating-service/src/main/resources/bootstrap.properties

@@ -53,7 +53,7 @@ dubbo.application.qos.enable=false
 dubbo.application.qos.port=28111
 dubbo.application.qos.accept.foreign.ip=false
 dubbo.application.name=${spring.application.name}-dubbo
-
+dubbo.registry.group=
 
 dubbo.reference.com.foo.BarService.check=false
 dubbo.reference.check=false