remove chancfg.h

direct/src/showbase/showBase.cxx

@@ -20,7 +20,6 @@
 
 #include "throw_event.h"
 #include "graphicsWindow.h"
-#include "chancfg.h"
 #include "renderBuffer.h"
 #include "get_config_path.h"
 #include "camera.h"