libtracker-miner: Remove unneeded call to item_queue_handlers_set_up()
libtracker-miner: Remove unneeded call to item_queue_handlers_set_up()

item_add_or_update_cb() does not usually need to call this function as
the item queue is not stopped while waiting for extraction tasks. We
do need to call it if the queues are empty to ensure a QUEUE_NONE
event is processed.

hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker