[monasca-agent] Change tox to use https instead of git

This change is to work around proxy settings by using https

Change-Id: Ifc43e048cb2125e9b3452263493292e0017d4763

tools/tox_install.sh

@@ -11,6 +11,8 @@ requirements_installed=$(echo "import openstack_requirements" | python 2>/dev/nu
 
 set -e
 
+git config --global url.https://git.openstack.org/.insteadOf git://git.openstack.org/
+
 CONSTRAINTS_FILE=$1
 shift