Projects - display "members" link in disabled style if user can't edit project

Summary: Fixes T6862.

Test Plan: viewed a project list and saw disabled-style "Members" links as appropos

Reviewers: epriestley, chad

Reviewed By: chad

Subscribers: Korvin, epriestley

Maniphest Tasks: T6862

Differential Revision: https://secure.phabricator.com/D11229