[1.17.0] Missing en-US index key admin.monitor.queue.flush

### Description

Show 500 error
https://github.com/go-gitea/gitea/blob/main/templates/admin/queue.tmpl#L160

### Gitea Version

1.17.0

### Can you reproduce the bug on the Gitea demo site?

No

### Log Gist

_No response_

### Screenshots

_No response_

### Git Version

_No response_

### Operating System

Gentoo

### How are you running Gitea?

systemd

### Database

PostgreSQL