cmdutils: remove conditionnal pp include.

The definition of the include are needed for builds even without pp.
This should fix FATE with --disable-gpl after 63edd2f9.

cmdutils.c

@@ -36,9 +36,7 @@
 #include "libavresample/avresample.h"
 #include "libswscale/swscale.h"
 #include "libswresample/swresample.h"
-#if CONFIG_POSTPROC
 #include "libpostproc/postprocess.h"
-#endif
 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 #include "libavutil/bprint.h"