pt-osc大表变更bug

### 重现步骤

1.修改osc_recursion_method = none
2.在查询SQL菜单里执行，SQL会报错，数据脱敏异常：(2005, "Unknown MySQL server host 'goinception' (2)")

### 预期外的结果

1.修改osc_recursion_method = none
2.在查询SQL菜单里执行，SQL会报错，数据脱敏异常：(2005, "Unknown MySQL server host 'goinception' (2)")

### 日志文本

_No response_

### 版本

1.8.5

### 部署方式

Docker

### 是否还有其他可以辅助定位问题的信息？比如数据库版本等

_No response_

Start by reproducing the failure from the SQL query menu with osc_recursion_method set to none, using the Docker deployment and version 1.8.5. Trace how the query and data-masking flow resolves the goinception MySQL host, then verify that the query no longer fails with the reported unknown-host error.

Written by the indexing model from the issue text.