R1:0f2ec96275c3

Actually fix timeline icons

Summary: I need my eyes checked. The previous specificity was incorrect.

Test Plan: Stare really hard and inspect both major and minor timeline events in Chrome.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D8850