Revert of git_auto_svn.py: Rewrite http SVN URLs to https (patchset #3 id:40001 of https://codereview.chromium.org/745473003/)

Reason for revert:
This actually makes the Git mirrors unusable for git svn, since there's a mismatch between the svn remote URL and the URLs of the git-svn-id footers in each Git commit (which confuses scripts like git_cl.py and makes uploading and committing CLs impossible).

Original issue's description:
> git_auto_svn.py: Rewrite http SVN URLs to https
>
> BUG=435091
> TESTED=Ran the following:
> git clone https://chromium.googlesource.com/external/webrtc
> cd webrtc
> git auto-svn
> cat .git/config
> Verified the URL was using http before this patch, and https after applying it.
>
> R=agable@chromium.org, mmoss@chromium.org
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=293041

TBR=agable@chromium.org,mmoss@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=435091

Review URL: https://codereview.chromium.org/767913002

git-svn-id: http://src.chromium.org/chrome/trunk/tools/depot_tools@293148 4ff67af0-8c30-449e-8e8b-ad334ec8d88c