When user doesn't have permission to edit a Site the button looks disabled, but is clickable.

Setup:

1. Create a user "test" with permissions:

a) Content/*

b) Section/*

c) User/login: site,admin

        2. Create a Site in SiteFactory when logged as admin

Steps to reproduce:

1. Login as user "test"

2. Go to "Site" -> site factor

3. Go to details of the created Site in Site Factory

4. Click "Edit"

Expected:

Button is not clickable

Actual:

Button is clickable and Symfony AccessDenied page is shown in dev mode