Fixes fatal when searching for user projects in maniphest

Summary:
Adds the phids of users entered into any user project query to handles phids for handle loading

Fixes T3395

Test Plan: Load page that was previous breaking

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T3395

Differential Revision: https://secure.phabricator.com/D6250