What does this MR do?
Allows numeric domains for GitLab Pages - such as 123.example.com. Previously this was not allowed, despite this being a perfectly valid hostname.
Are there points in the code the reviewer needs to double check?
Why was this MR needed?
A customer in https://gitlab.zendesk.com/agent/tickets/77158 mentioned they are trying to migrate their static site to GitLab.com, but can't because their domain has
2014 in it.