Stop IPtables modification

Hi,

when using docker and setting iptables=false it's still messing with my iptables setup. False means that it is not touching iptables at all. The way this is treated in dockerd is unacceptable.

Stuff like this from the docs:

It is possible to set the iptables key to false in the Docker engine’s configuration file at /etc/docker/daemon.json, but this option is not appropriate for most users. It is not possible to completely prevent Docker from creating iptables rules, and creating them

Is completely inadmissible. When I tell software to stay away from my system configuration I expect it to do exactly that: stay away from it.

Docker - Debug your environment, then your app.

Cu

Start by reproducing the issue with Docker configured with iptables=false, then trace the libnetwork and daemon configuration handling involved. The issue provides no file or test location, so first identify where iptables rules are created and how the option is applied. Done means Docker makes no iptables changes when the option is false, with regression coverage for that behavior.