CC-4176: Smart Playlist: Set implicit item limit when user uses time as a limit
CC-4176: Smart Playlist: Set implicit item limit when user uses time as a limit

- done

sourcefabric/airtime,ReganDryke/airtime,Ryex/airtime,sourcefabric/Airtime,thnkloud9/Airtime,sourcefabric/Airtime,radiorabe/airtime,sourcefabric/airtime,comiconomenclaturist/libretime,Lapotor/libretime,comiconomenclaturist/libretime,radiorabe/airtime,sourcefabric/airtime,ReganDryke/airtime,sourcefabric/Airtime,comiconomenclaturist/libretime,Lapotor/libretime,justvanbloom/airtime,justvanbloom/airtime,LibreTime/libretime,justvanbloom/airtime,justvanbloom/airtime,Ryex/airtime,sourcefabric/airtime,ReganDryke/airtime,sourcefabric/airtime,Lapotor/libretime,LibreTime/libretime,comiconomenclaturist/libretime,ReganDryke/airtime,sourcefabric/airtime,ReganDryke/airtime,Lapotor/libretime,radiorabe/airtime,comiconomenclaturist/libretime,thnkloud9/Airtime,Ryex/airtime,sourcefabric/airtime,LibreTime/libretime,sourcefabric/Airtime,radiorabe/airtime,thnkloud9/Airtime,Lapotor/libretime,justvanbloom/airtime,ReganDryke/airtime,comiconomenclaturist/libretime,thnkloud9/Airtime,justvanbloom/airtime,Ryex/airtime,LibreTime/libretime,thnkloud9/Airtime,comiconomenclaturist/libretime,LibreTime/libretime,LibreTime/libretime,ReganDryke/airtime,sourcefabric/Airtime,thnkloud9/Airtime,thnkloud9/Airtime,Ryex/airtime,Ryex/airtime,sourcefabric/Airtime,radiorabe/airtime,sourcefabric/Airtime,Ryex/airtime,radiorabe/airtime,radiorabe/airtime,Lapotor/libretime,justvanbloom/airtime