Don't set a default "group by priority" in the task search engine
Summary:
See PHI42. Currently, `maniphest.search` incorrectly applies this default (group by priority) to all queries via Conduit.
The correct behavior is to apply no grouping constraint.
I think this is also a reasonable general behavior, and the current code seems to date from D6960 in 2013 and didn't seem particularly carefully considered.
This is a minor compatibility break -- saved queries which are more than 4 years old might change their group behavior. I'll note this in the change logs but expect essentially no one to be affected.
Test Plan: Ran a `maniphest.search` Conduit call and observed the underlying query. Before this change, it executed `ORDER BY priority, id`. After this change, it correctly executed `ORDER BY id` only.
Reviewers: chad
Reviewed By: chad
Differential Revision: https://secure.phabricator.com/D18459