Allow Maniphest filtering by "upforgrabs" explicitly
Summary:
Allow you to filter by "upforgrabs" to find unassigned tasks.
Test Plan:
Filtered by "upforgrabs".
Reviewed By: tuomaspelkonen
Reviewers: tuomaspelkonen, jungejason, aran
Commenters: aran
CC: sandra, anjali, aran, tuomaspelkonen, epriestley
Differential Revision: 365