Fix installer script - better default GitHub URL
Fix installer script - better default GitHub URL

I think that GitHub has patched some potential security problems, or I
just never realized (because I was always cloning as a user who already
had an SSH key set up) that I needed a public git repo location to clone
from: the https://github.com/<username>/<reponame>.git URLs accomplish
this.

sycobuny/rcfiles,sycobuny/rcfiles