Tagger.lookup_cd takes the first item of the cd_lookup_device setting with a plain split on the first comma, without stripping it or skipping empty items. picard.util.cdrom reads the same setting properly (strips the items, skips the empty ones).

With "/dev/sr0 , /dev/sr1" or " /dev/sr0 , /dev/sr1" the lookup tries to read " /dev/sr0 ", and with ", /dev/sr1" it reads "" (the default drive) instead of /dev/sr1.
  
Expected: the first non-empty, stripped item of the setting is used, and python-discid auto detection only when none is configured.