Fix setup from getRequiredClasses buggyboo
Summary:
D2470 added Package mailhandler, which was configured incorrectly in the getRequiredClasses function. this makes it like the other mail handlers
Reported at https://github.com/facebook/phabricator/issues/112
Test Plan: setup mode no longer fails
Reviewers: epriestley, jungejason, royklopper
Reviewed By: royklopper
CC: aran, Koolvin
Differential Revision: https://secure.phabricator.com/D2476