Don't link commit uri in Crumbs

Summary: These are not needed I think? and handy for cut and paste. Fixes T7628

Test Plan: cut and paste easier from commit hash.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T7628

Differential Revision: https://secure.phabricator.com/D15245