Don't show "View Wiki" reminder link if viewer has no access to Phriction

Summary: Fixes T6581.

Test Plan:

• Loaded project page with Phriction accessible, saw link.
• Loaded project page with Phriction uninstalled, no link.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T6581

Differential Revision: https://secure.phabricator.com/D10868