Use a gitolite-configured file to indicate whether gitolite has been configured with a key already. This keeps the image from re-installing the admin key if it has been deleted by a repo admin.

Note: If you remove the admin public key, you should be sure that you have configured gitolite.conf so other users have access to the gitolite-admin repo.
Merge pull request #1 from jesselang/master

Use a gitolite-configured file to indicate whether gitolite has been con...