DJ-Label shows NULL if string is empty

[pgrill79]

I have a concatenated string in the DJ-Label Field:

${name}, ${adressline1}, ${zip} ${town}

which works fine, but if e.g. one field is NULL, also null is shown, which looks "unlovely":

It would be great if the single NULL field would just be empty (in case of a concatenated string). In case the total expression leads to NULL, maybe the PK should be shown.