Issue:DPL allows transclusion of non-transcludable namespaces

Description:	DPL allows transclusion of non-transcludable namespaces
Extension / Version:	DPL   /   1.6.4
Type / Status:	Bug   /   open

Problem

On our wiki, we have some non-transcludable namespaces (which are also locked down by user). However, when using DPL, I can do something like:

 <DPL>
   namespace=SecuredNamespace
   include=*
   format=,<H3>[[%PAGE%|%TITLE%]]</H3>,<BR>,
 </DPL>

to get all the contents of that namespace. Yikes!