Stop trying to version-check libphutil in "Config"

Summary:
Ref T13395. No library with this name loads any more, so we can't version check it.

(Ideally, the version check stuff would be more graceful when it fails now, since it's required to load "Config" after I moved it off a separate page.)

Test Plan: Loaded "Config".

Maniphest Tasks: T13395

Differential Revision: https://secure.phabricator.com/D20995