Limit ip-routing and snat to seed hosts only

Even if kayobe itself limit [1] ip-routing and snat playbooks to the
seed hosts only the playbooks should have same hosts specified.

TrivialFix

1. https://github.com/openstack/kayobe/blob/52d7523c0c3e6a6f7f321459b9d7fc055282057f/kayobe/cli/commands.py#L610



Change-Id: I35788e69eeace41d5bcbf89922145f1c35f58ff2
Signed-off-by: Maksim Malchuk <maksim.malchuk@gmail.com>