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/filesystem/wrap_File.cpp

@@ -435,7 +435,7 @@ const luaL_Reg w_File_functions[] =
 
 extern "C" int luaopen_file(lua_State *L)
 {
-	return luax_register_type(L, File::type, w_File_functions, nullptr);
+	return luax_register_type(L, &File::type, w_File_functions, nullptr);
 }
 
 } // filesystem