Fixes port.id bug added with 777a307b3c9f4284facf081e6b951b5755333adf

Changing port.id to port['id']


Change-Id: I1bd3759e17abd8c61050c48a3c8d70359eaeb8ad
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index 2b2f8ac..4ef9a87 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -223,7 +223,7 @@
                 port = self._create_port(network_id=net_id,
                                          client=clients.ports_client,
                                          **create_port_body)
-                ports.append({'port': port.id})
+                ports.append({'port': port['id']})
             if ports:
                 kwargs['networks'] = ports
             self.ports = ports