add sleep 1 to loop

(cherry picked from commit cc444c73d5)

bin/tests/system/dlzexternal/tests.sh

@@ -66,6 +66,7 @@ for i in 0 1 2 3 4 5 6 7 8 9; do
     ret=0
     grep 'dlz_example: shutting down zone example.nil' ns1/named.run > /dev/null 2>&1 || ret=1
     [ "$ret" -eq 0 ] && break
+    sleep 1
 done
 [ "$ret" -eq 0 ] || echo "I:failed"
 status=`expr $status + $ret`