Add php5 vhost for main wiki

Provision a vhost running the primary wiki using php5's mod_php
interpreter. This can be useful when debugging php5 vs hhvm behavior
differences. The vhost is available at http://php5.local.wmftest.net:8080/

Bug: 67517
Change-Id: I43ab9de1bdf4e1a1118752b73a3161c586b12854
Merge "Add php5 vhost for main wiki"