If an http(s)-based git repository needs credentials to access, but the user

doesn't want to put the credentials into the URL, it's not possible to add it.

The problem is that even though the repository isn't used to access files

(since we use the raw file URL mask for that), we still try to do 

git ls-remote on it.
With this change, if the user added credentials to the admin UI, we'll now

patch those credentials into the URL passed into ls-remote.

Ran unit tests.