Prune shellserver/PHP7 unit
Summary:
Contains only a cgi.force_redirect = 0 for SuEXEC, unused.
Plan is to use nginx + php-fpm ondemand if PHP hosting is asked on Eglide.
Ref T1325.
Test Plan: no op
Reviewers: dereckson
Reviewed By: dereckson
Maniphest Tasks: T1325
Differential Revision: https://devcentral.nasqueron.org/D1476