[lmu2png] 24-bit and higher tilesets are unsupported

[lumiscosity]

24-bit images are unsupported by lmu2png despite being supported by EasyRPG; this causes maps with 24-bit images to not provide a picture.

[lumiscosity]

might be related to the chipset code? if i'm reading this correctly it assumes the chipset is 8bit and tries to "precalculate" on an 8bit surface

Tools/lmu2png/src/chipset.cpp

Line 32 in e7b73e8

 ChipsetSurface  = SDL_CreateRGBSurface(0, 32 * 16, 45 * 16, 8, 0, 0, 0, 0);