Disable dns-integration in Neutron in Fedora job

Because of bug [1] in dnsmasq in Fedora 28 we need to disable
dns-integration in Neutron for this job as a workaround of this problem.

When dns integration is disabled, Neutron will not set hostname for port
to be same as VM's name thus this dnsmasq bug will not be triggered.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1695647

Change-Id: Id3e5c1095b5de0c56527a233ff04b66374128973

zuul.d/tobiko-devstack.yaml

@@ -33,7 +33,11 @@
         h-api-cfn: true
         h-eng: true
         n-cpu: false
-        neutron-dns: true
+        # NOTE(slaweq): we need to enable it as "legacy" service because for Fedora job
+        # it has to be disabled. If it would be disabled as "neutron-dns: false" then it
+        # devstack would consider that neutron-legacy isn't used and would not load proper
+        # files
+        q-dns: true
         neutron-qos: true
         neutron-segments: true
         neutron-trunk: true
@@ -128,8 +132,14 @@
     nodeset: openstack-three-node-fedora-28
     voting: false
     vars:
+      devstack_localrc:
+        # Add dns-domain-ports,dns-integration extensions again when bug
+        # https://bugzilla.redhat.com/show_bug.cgi?id=1695647
+        # will be fixed for Fedora
+        NETWORK_API_EXTENSIONS: address-scope,agent,allowed-address-pairs,auto-allocated-topology,availability_zone,binding,default-subnetpools,dhcp_agent_scheduler,dvr,empty-string-filtering,ext-gw-mode,external-net,extra_dhcp_opt,extraroute,filter-validation,fip-port-details,flavors,ip-substring-filtering,l3-flavors,l3-ha,l3_agent_scheduler,logging,metering,multi-provider,net-mtu,net-mtu-writable,network-ip-availability,network_availability_zone,pagination,port-security,project-id,provider,qos,qos-bw-minimum-ingress,qos-fip,quotas,quota_details,rbac-policies,router,router_availability_zone,security-group,port-mac-address-regenerate,port-security-groups-filtering,segment,service-type,sorting,standard-attr-description,standard-attr-revisions,standard-attr-segment,standard-attr-timestamp,standard-attr-tag,subnet_allocation,trunk,trunk-details,uplink-status-propagation
       devstack_services:
         tls-proxy: false
+        q-dns: false
     group-vars:
       subnode:
         devstack_services: