Remove field albumartist from minimserver

[simoncn]

You can use two mscript commands like this:

./mscript -c "prop aliasTags=AlbumArtist:nil"
./mscript -c rescan

or you can enter the commands interactively like this:

./mscript
prop aliasTags=AlbumArtist:nil
rescan

then enter a null line to exit from mscript