Fix missing EditEngineConfig on indirect pathway through conduit.query

Summary: Fixes T9772. We now need an EditEngineConfiguration to do interesting things with EditEngine, but this public API wasn't properly making sure we have one.

Test Plan: Called conduit.query from web console. Fatal prior to patch; success afterward.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9772

Differential Revision: https://secure.phabricator.com/D14475