GH and BON evaluations links from the admin gadget are shown to non system admins

1. Create an 'JIRA Admin' only user (i.e. a user with JIRA Administrators permission but not JIRA System Administrators permission)
2. Make sure you have websudo permission already by visiting an admin page. If you don't do this you will hit JRA-27819.
3. Goto a dashboard with the admin gadget.
4. (BUG) Click on the "Install GH" or "Install Bon" link. You will end up with a horrible dialog with 401 error.

As only JIRA System Administrators have permissions to install plugins, I would assume that these links should not be visible admins without this permission.