Increase chime spawn rate at Twisted Treeline

If you played you probably noticed already chimes spawn first 2 at a time, then 3, then as game passes increasing. However the spawn rate is restricted to map size, so 2 chime spawn in a certain map size. In twisted treeline the map is smaller, so less chimes spawn at a time. succesfull wanderers should be a bit more rewarded, so they won't fall out late game with his low scalings.