Pass Type to luax_register_type by pointer instead of reference

Since the type is passed to va_start, and apparently that's undefined behaviour if it's a reference.

<Textmode> the best kind of behavior

--HG--
branch : dynamiccore2

src/modules/graphics/opengl/wrap_Graphics.cpp

@@ -2090,7 +2090,7 @@ static const luaL_Reg functions[] =
 
 static int luaopen_drawable(lua_State *L)
 {
-	return luax_register_type(L, Drawable::type, nullptr);
+	return luax_register_type(L, &Drawable::type, nullptr);
 }
 
 // Types for this module.