Use ipv4 address for connectivity in lb integration test

You can not specify subnet for a server creation. Therefore server
nic would get ip adresses from all subnets. We should pick the
ipv4 address to check connectivity.

Also added change to NovaClientPlugin to provide ipv4 address.

Change-Id: I2eb3bdb359aca0cfaebf0be98db79170c681a078
Closes-Bug: #1450293
diff --git a/scenario/templates/test_neutron_loadbalancer.yaml b/scenario/templates/test_neutron_loadbalancer.yaml
index 3014356..b0c48c2 100644
--- a/scenario/templates/test_neutron_loadbalancer.yaml
+++ b/scenario/templates/test_neutron_loadbalancer.yaml
@@ -119,10 +119,10 @@
       - { get_resource: server1 }
 
 outputs:
-  serv1_ip:
-    value: {get_attr: [server1, networks, private, 0]}
-  serv2_ip:
-    value: {get_attr: [server2, networks, private, 0]}
+  serv1_addresses:
+    value: {get_attr: [server1, addresses, private]}
+  serv2_addresses:
+    value: {get_attr: [server2, addresses, private]}
   vip:
     value: {get_attr: [test_pool, vip, address]}
   fip:
diff --git a/scenario/test_neutron_loadbalancer.py b/scenario/test_neutron_loadbalancer.py
index 2d852b3..61642d1 100644
--- a/scenario/test_neutron_loadbalancer.py
+++ b/scenario/test_neutron_loadbalancer.py
@@ -69,9 +69,10 @@
         stack = self.client.stacks.get(sid)
         floating_ip = self._stack_output(stack, 'fip')
         vip = self._stack_output(stack, 'vip')
-        server1_ip = self._stack_output(stack, 'serv1_ip')
-        server2_ip = self._stack_output(stack, 'serv2_ip')
-
+        server1_ip = self._get_server_ip_by_version(
+            self._stack_output(stack, 'serv1_addresses'))
+        server2_ip = self._get_server_ip_by_version(
+            self._stack_output(stack, 'serv2_addresses'))
         # Check connection and info about received responses
         self.check_connectivity(server1_ip)
         self.collect_responses(server1_ip, {'server1\n'})