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.
In TOR don't appears the "New Tab" Button, and I can only open tabs using Ctrl + T
But the button still appearing when i want to personalize the browser
My actual version is 6.0.1 (based on Mozilla Firefox 45.2.0).