Update gitlab-config repository location (#17753)

wiki/src/contribute/working_together/roles/sysadmins.mdwn

@@ -253,7 +253,7 @@ Below, importance level is evaluated based on:
   - Tails system administrators have administrator credentials inside GitLab.
   - Groups, projects, and access control:
      - [[high-level documentation|working_together/GitLab#access-control]]
-     - configuration: `gitlab-config` repository (hosted on `puppet-git.lizard`)
+     - configuration: [[!tails_gitlab tails/gitlab-config]]
 * importance: critical (needed to release Tails)
 * Tails system administrators administrate this GitLab instance.