gitlab:check complaining about valid git user ssh files.

Summary

rake gitlab:check:app includes a check for Git user has default SSH configuration? that throws errors for valid files.

Specifically:

/var/opt/gitlab/.ssh/id_rsa.pub
/var/opt/gitlab/.ssh/authorized_keys.lock
/var/opt/gitlab/.ssh/id_rsa

The git user's rsa keys are generated by Omnibus for GitLab Geo. And the authorized_keys.lock is created and used by gitlab-shell.