Rework initial checkout code for submodules.
Rework initial checkout code for submodules.

Instead of just using the initial upstream submodule URL when performing an
initial git submodule update, rewrite the URL to match what is in
DEV_REMOTE_SOURCES for the upstream remote for the branch the submodule was
imported from.

mmnelemane/crowbar,toabctl/crowbar,tserong/crowbar,toabctl/crowbar,nkrinner/crowbar,SUSE-Cloud/crowbar,vwallfahrer/crowbar,mmnelemane/crowbar,rsalevsky/crowbar,dirkmueller/crowbar,dirkmueller/crowbar,aplanas/crowbar,rhafer/crowbar,vwallfahrer/crowbar,MaximilianMeister/crowbar,tserong/crowbar,aplanas/crowbar,aspiers/crowbar,rhafer/crowbar,SUSE-Cloud/crowbar,aspiers/crowbar,MaximilianMeister/crowbar,rhafer/crowbar,nkrinner/crowbar,rsalevsky/crowbar,crowbar/crowbar,crowbar/crowbar