Removed unused buildApplicationPage method from PhabricatorController
Summary: Getting rid of some code! This method has no callsites so it should be safe to remove completely. Ref T9690
Test Plan: Removed method and clicked around to make sure nothing broke.
Reviewers: Blessed Reviewers, epriestley
Reviewed By: Blessed Reviewers, epriestley
Subscribers: yelirekim, epriestley
Maniphest Tasks: T9690
Differential Revision: https://secure.phabricator.com/D16439