Correctly fetch the ips from server

In _check_tenant_network_connectivity(), server's ips are not fetched
correctly. Current code throw KeyError as mentioned in bug.

This patch fix the above issue.

Change-Id: Ibf9b3997b927a66c507f04e2671faf9cb8581ff3
Closes-Bug: #1401028
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index 410d90a..dedb17a 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -751,9 +751,9 @@
         # The target login is assumed to have been configured for
         # key-based authentication by cloud-init.
         try:
-            for net_name, ip_addresses in server['networks'].iteritems():
+            for net_name, ip_addresses in server['addresses'].iteritems():
                 for ip_address in ip_addresses:
-                    self.check_vm_connectivity(ip_address,
+                    self.check_vm_connectivity(ip_address['addr'],
                                                username,
                                                private_key,
                                                should_connect=should_connect)