Fix another per-map tile regression that could cause tiles to fail to load
I didn't realize in the previous per-map changes that the faketile array shifts the tile indices right by 3. As a result, I didn't check the proper index in the tilefilenum array.
For this array I think it's fine to restore the entirety of it, otherwise problems can occur where it thinks that certain entries are still filled with a dummy tile when loading the next per-map tile.
Hopefully, this is the last per-map art problem.