Replace openstack.org git:// URLs with https://

This is a mechanically generated change to replace openstack.org
git:// URLs with https:// equivalents.

This is in aid of a planned future move of the git hosting
infrastructure to a self-hosted instance of gitea (https://gitea.io),
which does not support the git wire protocol at this stage.

This update should result in no functional change.

For more information see the thread at

 http://lists.openstack.org/pipermail/openstack-discuss/2019-March/003825.html

Change-Id: I5f8342770126c424a40ad1b60c4dddf283cf76f5

quickstart.sh

@@ -140,7 +140,7 @@ bootstrap () {
             pushd $EXTRAS_DIR
                 $ZUUL_CLONER --cache-dir \
                     /opt/git \
-                    git://git.openstack.org \
+                    https://git.openstack.org \
                     openstack/tripleo-quickstart-extras
                 cd openstack/tripleo-quickstart-extras
                 if [ $OPT_CLEAN == 1 ]; then