Allow PHP to be built by builder user
Currently, a parameter error makes PHP be built as root.
This change enables the less privileged build process
to actually work.
This is a follow-up for d07877e8.
Test Plan: salt-call --local state.sls roles/webserver-legacy/php-builder
Reviewed By: dereckson
Differential Revision: https://devcentral.nasqueron.org/D2092