Drop unused tun_network_interface property

Related-Prod: PRODX-3456
Change-Id: I373d069cf6c079246f0ffc074f496e45df774f48
diff --git a/de/heat-templates/top.yaml b/de/heat-templates/top.yaml
index e6c70d3..7849851 100644
--- a/de/heat-templates/top.yaml
+++ b/de/heat-templates/top.yaml
@@ -159,10 +159,6 @@
   tun_network_pool_end:
     type: string
     default: '10.15.0.99'
-  tun_network_interface:
-    type: string
-    default: 'ens8'
-    description: 'The name of interface that should be used by vrouter in deployment with TF'
   ucp_metadata:
     type: json
     default: {"role":"ucp"}