add gateway for different vlan to group_vars

group_vars/all.yaml.example

@@ -1,6 +1,8 @@
 ---
-# The name (as defined in the inventory) of the external gateway.
-ext_gateway: ""
+# ip of the management vlan gateway
+management_gateway: 0.0.0.0
+# ip of the vm vlan gateway
+vm_gateway: 0.0.0.0
 # Put here the public key of the users CA.
 user_ca_key: ""
 # Put here the public ip for your organisation