mrhlpr: add support for GNOME SSH origin (MR 54)

GNOME's SSH endpoints areof the form
git@ssh.gitlab.gnome.org:GNOME/Incubator/papers.git and without this
patch, the host could not be found

mrhlpr/gitlab.py

@@ -146,7 +146,7 @@ def parse_git_origin() -> GitLabOrigin:
     ]
     for domain in domains:
         prefixes = [
-            r"^git@" + domain.replace(".", "\\.") + ":",
+            r"^git@(ssh\.)?" + domain.replace(".", "\\.") + ":",
             r"^https:\/\/(?:[^\s\@\/]*@)?" + domain.replace(".", "\\.") + "\\/",
         ]
         host = None