R1:fed0a2a49653

Fix search and core icons in top nav

Summary: Fixes T3330

Test Plan: Test desktop and mobile menus in chrome and ios.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T3330

Differential Revision: https://secure.phabricator.com/D6157