Fix nullref error on re-importing a DeletePending beatmap
Fix nullref error on re-importing a DeletePending beatmap

Callback was expecting the beatmap to be populated where it wasn't being.
Drezi126/osu,johnneijzen/osu,smoogipoo/osu,naoey/osu,EVAST9919/osu,Frontear/osuKyzer,smoogipoo/osu,peppy/osu,ppy/osu,Nabile-Rahmani/osu,NeoAdonis/osu,peppy/osu,2yangk23/osu,UselessToucan/osu,Damnae/osu,johnneijzen/osu,DrabWeb/osu,DrabWeb/osu,ppy/osu,NeoAdonis/osu,UselessToucan/osu,EVAST9919/osu,naoey/osu,NeoAdonis/osu,ZLima12/osu,smoogipoo/osu,2yangk23/osu,DrabWeb/osu,smoogipooo/osu,ZLima12/osu,peppy/osu,naoey/osu,peppy/osu-new,ppy/osu,UselessToucan/osu