Fix backward compatibility with single network engine definitions.

Change-Id: Ib022b5b3bfdac630312c97b06ca100b0ef4a1673
diff --git a/tests/pillar/pool_contrail4_0.sls b/tests/pillar/pool_contrail4_0.sls
index 3b0595c..612187f 100644
--- a/tests/pillar/pool_contrail4_0.sls
+++ b/tests/pillar/pool_contrail4_0.sls
@@ -48,9 +48,8 @@
       kube_proxy: DFvQ8GelB7afH3wClC9romaMPhquyyEe
     ca: kubernetes
     network:
-      cnis:
-      - opencontrail
-      contrail:
+      opencontrail:
+        enabled: true
         version: 4.0
         config:
           api: