repo-config is no longer supported by any upstream-supported
git version. Instead, use git config (which is implicitly
git config --file, corresponding to the earlier config-in-repo).
Every time you start qgit, or refresh a repo, you get a popup
saying that repo-config is not recognized. This makes qgit
annoying to use at best. Unless you have a really old git
installed, the intent of the config option is broken.