fix conpherence menu selection
Summary: i think the DOM changed in conpherence with the menu upgrades. just noticed that when you select a new conpherence the old one is not de-selected. this fixes it by updating the javascript to ascend one node higher and then use DOM.scry with the right data sigil to get the nodes
Test Plan: read some messages, noted only the one I was reading had the entry highlighted in the left.
Reviewers: epriestley
Reviewed By: epriestley
CC: aran, Korvin
Maniphest Tasks: T2399
Differential Revision: https://secure.phabricator.com/D4819