R1:3ce3ce957d3f

Clean up css race condition in Conpherence notification menu

Summary: Depending on when packages loaded, this CSS sometimes gets overwritten. Make it more specific and always present.

Test Plan: Reload a lot

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D16657