sql: fix historical issues

database/update.sql

@@ -296,3 +296,8 @@ CHANGE `show` `show` tinyint(1) NOT NULL DEFAULT '0' COMMENT '是否显示' AFTE
 
 ALTER TABLE `v2_server_trojan`
 ADD `server_name` varchar(255) NULL AFTER `allow_insecure`;
+
+SELECT *
+FROM `v2_server`
+WHERE `ruleSettings` = '{}'
+LIMIT 50