Fixes #6479/BZ1115633: hide product content edit button if applicable

If the user does not have permission do not show the product content
edit button.

http://projects.theforeman.org/issues/6479
https://bugzilla.redhat.com/show_bug.cgi?id=1115633
Merge pull request #4383 from waldenraines/6479

Fixes #6479/BZ1115633: hide product content edit button if applicable