Remove unused System.Drawing reference.
Remove unused System.Drawing reference.

UselessToucan/osu,naoey/osu,2yangk23/osu,EVAST9919/osu,johnneijzen/osu,peppy/osu,EVAST9919/osu,smoogipooo/osu,DrabWeb/osu,Frontear/osuKyzer,Drezi126/osu,ppy/osu,default0/osu,NeoAdonis/osu,DrabWeb/osu,RedNesto/osu,peppy/osu,smoogipoo/osu,UselessToucan/osu,NeoAdonis/osu,naoey/osu,ppy/osu,ppy/osu,tacchinotacchi/osu,peppy/osu,nyaamara/osu,smoogipoo/osu,Nabile-Rahmani/osu,Damnae/osu,smoogipoo/osu,ZLima12/osu,NotKyon/lolisu,ZLima12/osu,DrabWeb/osu,osu-RP/osu-RP,NeoAdonis/osu,johnneijzen/osu,peppy/osu-new,2yangk23/osu,theguii/osu,naoey/osu,UselessToucan/osu