Fix Pokémon Mansion encounters.
Fix Pokémon Mansion encounters.

There was a mix up with B1F and 1F in FireRed and LeafGreen.
Both floors got labeled as 1F during the location area cleanup,
and the B1F encounters were copied to 2F and 3F instead of the 1F
encounters.

veekun/pokedex,veekun/pokedex