Skip test_subnet_details

Rather than a full revert, skip test_subnet_details until timeouts/delays
have been added and the test is stabilized.

Change-Id: Iac6603ae3efc8588756c02ae2c1ab03a9df615e9
Related-bug: #1412325
diff --git a/tempest/scenario/test_network_basic_ops.py b/tempest/scenario/test_network_basic_ops.py
index 2cfec14..ebc6b15 100644
--- a/tempest/scenario/test_network_basic_ops.py
+++ b/tempest/scenario/test_network_basic_ops.py
@@ -436,6 +436,7 @@
                                  act_serv=servers,
                                  trgt_serv=dns_servers))
 
+    @test.skip_because(bug="1412325")
     @testtools.skipUnless(CONF.scenario.dhcp_client,
                           "DHCP client is not available.")
     @test.attr(type='smoke')