glx extension fix for GLX windowing api

Engine/source/gfx/gl/tGL/tXGL.h

@@ -30,7 +30,7 @@
 #include "tGL.h"
 #include <glad/glad_glx.h>
 
-#define gglHasXExtension(display, screen, EXTENSION) 
+#define gglHasXExtension(display, screen, EXTENSION) GLAD_GLX_##EXTENSION
 
 #endif //TORQUE_OS_LINUX