Updated the gitlab_git gem

**What does this do?**
It updated the version of gitlab_git to the latest version

**Why is this needed?*
There was a bug in rugged (dependency of gitlab_git) that causes a segfault
error when seeding the database. That error has been fixed and the fix is in the
latest version of gitlab_git

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>