Summary: If no ssh keys are in phabricator, bin/ssh-auth errors with undefined `$lines`. This fixes that case and explicitly tells the user no rows were found.
Test Plan: Ran bin/ssh-auth before and after change with no ssh keys in the system. Error goes away after change.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: epriestley
CC: epriestley, aran, Korvin
Differential Revision: https://secure.phabricator.com/D7675
45c3a605ee