allow for empty pkgs
allow for empty pkgs

Test Plan: didn't test :/

Reviewers: kylec

Reviewed By: kylec

Subscribers: changesbot, wwu, mkedia, klai, cam

Differential Revision: https://tails.corp.dropbox.com/D135392

wfxiang08/changes,dropbox/changes,dropbox/changes,wfxiang08/changes,wfxiang08/changes,dropbox/changes,dropbox/changes,wfxiang08/changes