fix:删除预警分类错误提示

services/edb_monitor/edb_monitor_classify.go

@@ -193,6 +193,7 @@ func DeleteEdbMonitorClassify(req request.EdbMonitorClassifyDeleteReq) (msg stri
 	}
 	if count > 0 {
 		msg = "分类下存在关联预警，不能删除"
+		err = fmt.Errorf("分类下存在关联预警，不能删除")
 		return
 	}
 	err = edbmonitor.DeleteEdbMonitorClassifyByIdList(classifyIds)