Fix 500 error when group name ends with git

What does this MR do?

Use ' instead of " in regex string. This will prevent invalid regular expression

Why was this MR needed?

Fix 500 error when group name ends with git

Does this MR meet the acceptance criteria?

• Changelog entry added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

https://gitlab.com/gitlab-com/support-forum/issues/1298, https://gitlab.com/gitlab-org/gitlab-ce/issues/24742