Git Annex `ssh://` Git URL doesn't work

• Zendesk ticket: https://gitlab.zendesk.com/agent/tickets/13919
• Dev link: None
• GitLab version: Unknown

Expected behavior

If a GitLab install uses a non-standard SSH port users will need to use a clone URL of format ssh://git@gitlab.example.com:2222/group/project.git. In this case git-annex does not seem to work.

Observed behavior

Normal git operations work fine with the above URL format, but when attempting to interact with annex users receive: Remote origin does not have git-annex installed; setting annex-ignore.

Next steps

I can reproduce this in my testing. @marin should this URL format work? Is there anything blocking support for this or is it just a bug? Thanks for taking a look.