Missing cmake check for Xrender

[Alexander Neundorf]

On Thursday 29 January 2009, Allen Winter wrote:
...
> Ok, I took care of this.
> kfilepreviewgenerator can now build with or without Xrender.
> And the kdelibs CMakeLists.txt will print a logging message about Xrender
> discovery.

In kdelibs/kfile/CMakeLists.txt ? 
I don't see it a test (except the one for linking).

Alex