Fix urlPresence to return null on blank/null string
Fix urlPresence to return null on blank/null string

Can't reset attribute by assigning undefined:

    someDom.style.backgroundImage = undefined

doesn't do anything.

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