Make ShowFpsEffectConfig build without GL dep

Forward declarations to the help!

effects/showfps/showfps.h

@@ -24,11 +24,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QtCore/QTime>
 
 #include <kwineffects.h>
-#include <kwinglutils.h>
 
 
 namespace KWin
 {
+class GLTexture;
 
 class ShowFpsEffect
     : public Effect

effects/showfps/showfps_config.cpp

@@ -19,6 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 
 #include "showfps_config.h"
+#include "showfps.h"
 
 #include <kwineffects.h>
 

effects/showfps/showfps_config.h

@@ -24,7 +24,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <kcmodule.h>
 
 #include "ui_showfps_config.h"
-#include "showfps.h"
 
 namespace KWin
 {