Disable protection in case there aren't any restriction types

This change disables the protection form and hides the protect
links in case there aren't any restriction types avialable.
Having no restriction types available let to a PHP notice and an
uggly, broken form. This became necessary as there are cases
in which no restriction types are avialable (caused by extensions)
eg. https://gerrit.wikimedia.org/r/34662

Change-Id: I0e5d3cfb299808ca14ead6baec0a18091acaa2b2