Skip test_create_zone_using_not_existing_tld

With wrong test TLD the zone creates successful
if environment hasn't any TLD's.

Related-Issue: PRODX-29973
Change-Id: I9094297f24c8b473f6455cc1a982ed5100788fb6
diff --git a/designate_tempest_plugin/tests/scenario/v2/test_tld.py b/designate_tempest_plugin/tests/scenario/v2/test_tld.py
index 27614e0..5f5a019 100644
--- a/designate_tempest_plugin/tests/scenario/v2/test_tld.py
+++ b/designate_tempest_plugin/tests/scenario/v2/test_tld.py
@@ -12,6 +12,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import testtools
+
 from oslo_log import log as logging
 from tempest import config
 from tempest.lib import decorators
@@ -56,6 +58,8 @@
             self.wait_zone_delete, self.zones_client, zone['id'])
 
     @decorators.idempotent_id('06deced8-d4de-11eb-b8ee-74e5f9e2a801')
+    @testtools.skipIf(not CONF.dns.existing_tlds,
+                      "Skip because it doesn't match TLD configuration.")
     def test_create_zone_using_not_existing_tld(self):
         LOG.info('Try to create a Zone using not existing TLD:"{}"'.format(
             self.tld_name[::-1]))