Fixed the scripts struggling with nested API tables

I actually don't remember what the RoomData's lua references where for,
but I'm pretty srue it wasn't this. I'll figure something out when I've
had a sleep.

server/rooms/room_system_api.cpp

@@ -48,7 +48,7 @@ int openRoomSystemAPI(lua_State* L) {
 
 	//push the substable
 	for (const luaL_Reg* lib = libs; lib->func; lib++) {
-		lua_pushcfunction(L, lib->func);
+		lib->func(L);
 		lua_setfield(L, -2, lib->name);
 	}
 	return 1;