make test: fix failure on centos

Change-Id: I1fcc742699a60ef99ce97b35f7b964ee6ad29ddf
Signed-off-by: Klement Sekera <ksekera@cisco.com>
diff --git a/test/test_acl_plugin_l2l3.py b/test/test_acl_plugin_l2l3.py
index 97675d4..b971610 100644
--- a/test/test_acl_plugin_l2l3.py
+++ b/test/test_acl_plugin_l2l3.py
@@ -346,7 +346,7 @@
         all_rules = []
         for old_acl in orig_acls:
             for rule in old_acl.r:
-                all_rules.append(dict(vars(rule)))
+                all_rules.append(dict(rule._asdict()))
 
         # Add a few ACLs made from shuffled rules
         shuffle(all_rules)