Tweak seed element NAT rules.
Tweak seed element NAT rules.

To be able to route traffic to the bootstack control plane, we need to
not mangle it when the traffic is from te kvm host. Libvirt uses
192.168.122.1 as the host IP.

Change-Id: I6ca107ddab2b7d5c3a8ca1233f2f9f2ead11db74

radez/tripleo-image-elements,rdo-management/tripleo-image-elements,agroup/tripleo-puppet-elements,openstack/tripleo-image-elements,qwefi/tripleo-image-elements,agroup/tripleo-puppet-elements,qwefi/tripleo-image-elements,radez/tripleo-image-elements,openstack/tripleo-image-elements,agroup/tripleo-puppet-elements,qwefi/tripleo-image-elements,qwefi/tripleo-image-elements,qwefi/tripleo-image-elements,rdo-management/tripleo-image-elements,agroup/tripleo-puppet-elements