Fix editor background not being correctly cleaned up on forced exit
Fix editor background not being correctly cleaned up on forced exit

Closes #11214. Should be pretty obvious why.

UselessToucan/osu,NeoAdonis/osu,peppy/osu,UselessToucan/osu,peppy/osu,NeoAdonis/osu,ppy/osu,peppy/osu,smoogipoo/osu,ppy/osu,smoogipooo/osu,smoogipoo/osu,smoogipoo/osu,UselessToucan/osu,NeoAdonis/osu,ppy/osu,peppy/osu-new