Core: Fix getting config directory on Windows (fixes #1974)
Core: Fix getting config directory on Windows (fixes #1974)

mgba-emu/mgba,mgba-emu/mgba,libretro/mgba,Iniquitatis/mgba,Iniquitatis/mgba,libretro/mgba,Iniquitatis/mgba,mgba-emu/mgba,libretro/mgba,Iniquitatis/mgba,mgba-emu/mgba,libretro/mgba,libretro/mgba