Fix dict.values usage

In python3, dict.values() doesn't return a list,
but rather returns a view that can be iterated upon.

https://www.python.org/dev/peps/pep-3106/
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>

Change-Id: If274f85049f91243934f9e649fce86c49dbbbf1b
diff --git a/manila_tempest_tests/tests/scenario/manager_share.py b/manila_tempest_tests/tests/scenario/manager_share.py
index da8a8e5..4593e9a 100644
--- a/manila_tempest_tests/tests/scenario/manager_share.py
+++ b/manila_tempest_tests/tests/scenario/manager_share.py
@@ -291,7 +291,7 @@
         if instance and not ip:
             try:
                 net_addresses = instance['addresses']
-                first_address = net_addresses.values()[0][0]
+                first_address = list(net_addresses.values())[0][0]
                 ip = first_address['addr']
             except Exception:
                 LOG.debug("Instance has no valid IP address: %s", instance)