"This file is managed by gitlab-ctl. Manual changes will be erased!"

What does this MR do?

This merge request replaces the word "gitlab.yml" with the word "gitlab.rb" in one section of the admin area.

Are there points in the code the reviewer needs to double check?

No.

Why was this MR needed?

Configuration is no longer done in gitlab.yml, which is overwritten by gitlab-ctl.

What are the relevant issue numbers?

None.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together