www/gitlab: fix regression from 335fc7c38d61142727cb9f01fd9e401c476e4ad8

Gitlab requires net-http 0.4.1:
Because faraday >= 2, < 2.5 could not be found in locally installed gems
  and faraday >= 2.5, < 2.12.1 could not be found in locally installed gems,
  faraday >= 2, < 2.12.1 cannot be used.
And because faraday >= 2.12.1 depends on faraday-net_http >= 2.0, < 3.5,
  faraday >= 2 requires faraday-net_http >= 2.0, < 3.5.
Because faraday-net_http >= 3.4.0 depends on net-http >= 0.5.0
and faraday-net_http >= 2.0, < 3.4.0 could not be found in locally installed
gems,
  faraday-net_http >= 2.0 requires net-http >= 0.5.0.
Thus, faraday >= 2 requires net-http >= 0.5.0.
So, because Gemfile depends on faraday ~> 2
  and Gemfile depends on net-http = 0.4.1,
  version solving has failed.

While fixing the problem, moved gitlab used packages to own package names with a
PKGNAMESUFFIX of `-gitlab`.
This should make the gitlab package much more stable if updates in the ports are
done.