MFH: r452776

www/gitlab: Update from 9.3.11 to 9.4.7

Changelog: https://github.com/gitlabhq/gitlabhq/blob/v9.4.7/CHANGELOG.md

This update also fixes 4 security issues

Reviewed by: Matthias Fechner <idefix@fechner.net>

Approved by: ports-secteam (swills)