Proper zone cleanup after failed XFR.

src/knot/server/xfr-handler.c

@@ -231,10 +231,9 @@ static void xfr_task_cleanup(knot_ns_xfr_t *rq)
 		if (rq->flags & XFR_FLAG_AXFR_FINISHED) {
 			knot_zone_contents_deep_free(&rq->new_contents);
 		} else if (rq->data) {
-//			xfrin_constructed_zone_t *constr_zone = rq->data;
-//			knot_zone_contents_deep_free(&(constr_zone->contents));
-//			free(rq->data);
-//			rq->data = NULL;
+			knot_zone_contents_t *zone = rq->data;
+			knot_zone_contents_deep_free(&zone);
+			rq->data = NULL;
 		}
 	} else if (rq->type == XFR_TYPE_IIN) {
 		knot_changesets_t *chs = (knot_changesets_t *)rq->data;