Fix generated clone URLs for wikis on Geo secondaries

What does this MR do?

Fixes the URLs generated on a Geo secondary for wikis on the Geo primary

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

Why was this MR needed?

500 error when trying to view wiki clone instructions

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Review
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan

What are the relevant issue numbers?

Closes #4054 (closed)