R1:7463f9b3a9db

Only get phid if project exists

Summary: If a project phriction page already exists, but object does not, avoid a fatal error.

Test Plan: See https://github.com/facebook/phabricator/issues/123

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D2749