Clarify  type in User::addToGroup
Clarify  type in User::addToGroup

LiquidPL/osu-web,LiquidPL/osu-web,notbakaneko/osu-web,nanaya/osu-web,nanaya/osu-web,LiquidPL/osu-web,notbakaneko/osu-web,LiquidPL/osu-web,notbakaneko/osu-web,LiquidPL/osu-web,ppy/osu-web,notbakaneko/osu-web,ppy/osu-web,ppy/osu-web,nanaya/osu-web,ppy/osu-web,notbakaneko/osu-web,nanaya/osu-web,ppy/osu-web,nanaya/osu-web