This way an edited label can be filtered directly instead of during
update of the entire history_list.

This can be seen if someone has CashFusion running and the "Hide
CashFusions" option enabled and proceeds to rename a label to start with
"CashFusion ".
Without this fix the transaction is not hidden until the
wallet is restarted or the "Hide CashFusions" option is toggled off and
on.

This is to avoid a costly wallet.get_history() call.