fix, PEBKAC, compare alists' beef data pointer to NULL upon dt_io_clear_zones()
fix, PEBKAC, compare alists' beef data pointer to NULL upon dt_io_clear_zones()

Signed-off-by: Sebastian Freundt <b09d9bb16bf9b69282010dd0632eda7cd40aa71d@fresse.org>

rudimeier/dateutils,rudimeier/dateutils,rudimeier/dateutils