skip-auto-migrations is deprecated in favor of skip-auto-reconfigure

[LongLiveCHIEF]

Moving forward, gitlab is changing the name/locations of the auto-migrations file to be more in line with it's actual purpose (controlling how migrations are performed on a node during upgrades).

Current versions of Gitlab have a deprecation warning when detecting a /etc/gitlab/skip-auto-reconfigure, and notifies the user that moving forward from gitlab 11+ only /etc/gitlab/skip-auto-reconfigure will be supported.

See: https://github.com/voxpupuli/puppet-gitlab/blob/master/manifests/config.pp