Scanner: fix for tracks without number or disc
Scanner: fix for tracks without number or disc

spl0k/supysonic,nwokeo/supysonic,ezpuzz/supysonic,nwokeo/supysonic,ezpuzz/supysonic,hhm0/supysonic,nwokeo/supysonic,nwokeo/supysonic,nwokeo/supysonic,spl0k/supysonic,hhm0/supysonic,hhm0/supysonic,spl0k/supysonic