git-submodule-rewrite works great, but urls cannot be relative

[devinrhode2]

Our normal git repo's url is like: https://gitlab.our-co.com/usonly-projects/client-A in my .gitmodules file I had relative urls which are literally like: ../common-code - Somehow, these relative urls workaround an issue with authentication for cloning submodules in gitlab CI.

Anyway, I had to change these to the full urls for this script to work, which was very easy, I expect almost anyone else running into the issue will spot it and immediately know what to fix.

onward to a true monorepo. No more forking and and trying to sync submodules anymore.

[jeremysears]

Possible dup of #16 (or related).