Support SSH URI when Mirroring repositories
Problem to solve
When adding a repository mirror to "Mirroring repositories" configuration, Gitlab insists on using full standard URI like ssh://git@gitlab.com/gitlab-org/gitlab.git. However, when using SSH, Git uses shorter git@gitlab.com:gitlab-org/gitlab.git URI. It is annoying when copy&pasting URIs between repositories.
Proposal
Gitlab should understand the short repository URIs used by Git so that we can copy&paste them from "Clone with SSH" field.
