[FR] Auto remove indexed non-existing repository

[zhmyh]

I have checked the code and issues and found that in version 2 we had a pull request (#39) that introduced the new config option autoDeleteStaleRepos, which allowed us to automatically delete stale repositories. I did not find similar code and functionality in the latest version. It would be nice to have this functionality back so that non-existing (removed) repositories are automatically deleted when they are not accessible.

[zhmyh]

Found cleanup functionality which does what i need