quick, ghetto script to rescale profile pictures

Summary: we had a hole in scaling pics from oauth from a bit. that was patched in D2848. this cleans up the old data.

Test Plan: ran it in production. issue as described on task is resolved. also spot checked some profiles and they look good.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1634

Differential Revision: https://secure.phabricator.com/D3268