set_hooks_commit_msg used scp to download commit_msg hook even for
gerrit http(s) remote url. It will use scp for ssh remote url and
http(s) download for http(s) remote url (more proxy "friendly").
Note: this change modifies .gerrit/golden_site folder content (used
by tests), so delete .gerrit folder and run
"python -m git_review.tests.prepare".
Closes-bug: #1274876
Change-Id: I49bcf4fd84a88878f9381ddf1a8714b778688a0a