The reference implementation of the FWaaS iptables
agent/driver supports only one firewall per tenant
in Havana release. However, the FWaaS plugin will
let you create more than one firewall. This is
being fixed in this patch to not allow creating
the second firewall if a firewall already exists
for the tenant.
Change-Id: I8f1cad9791723ba919b5774a63982c204686ddfe
Closes-Bug: #1228442
2ab1c25f68