GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
The url in the about orbot points to https://torproject.org/android, which is a 404.
You probably want https://www.torproject.org/docs/android
[Automatically added by flyspray2trac: Operating System: All]