Conpherence - fix a bug
Summary: gotta idx() on this as the user may have no conpherences at all.
Test Plan: loaded up my 'noconpherences' user and observed no errors in the error log. my normal test user still worked okay too.
Reviewers: epriestley, garoevans
Reviewed By: garoevans
CC: aran, Korvin
Differential Revision: https://secure.phabricator.com/D5791