Statically disable iptables management for docker

Docker 1.13 changes the behaviour of iptables defaults from allow
to drop. This patch disables docker's iptables management as it was
in Docker 1.12 [1]

[1] https://github.com/docker/docker/pull/28257



Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>