Improve deprecation of git_data_dirs
In https://gitlab.com/gitlab-com/infrastructure/issues/2740, the git_data_dirs format changed and broke dev. It was difficult to understand what was broken and how things needed to be fixed.
I think we deprecated this in b9144d23, but I think this is going to make upgrading to 10.0 a bit challenging for GitLab.com. I also worry we'll have customers also breaking left and right. Could we:
- Improve the error message with a link to an explanation
I see that we had a warning message before, but I don't think any of us saw it. Should we consider preserving backwards compatibility but put a warning at the end of the reconfigure?