R1:67073f0d8af2

Clean up mobile css on config page

Summary: I seemed to have missed this, lots of funky desktop padding on mobile.

Test Plan: Review Config / Maniphest / etc on a mobile browser.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D16731