following the previous 0.7-safe commit, drop album-art entirely
following the previous 0.7-safe commit, drop album-art entirely

album-art defaulted to 0, and the replacement argument in 2.2 continues
to default to 0, so there is absolutely no point in keeping this argument
around.

REVIEW: 118664

KDE/phonon-vlc,KDE/phonon-vlc,BinChengfei/phonon-vlc,BinChengfei/phonon-vlc,BinChengfei/phonon-vlc,KDE/phonon-vlc