Comment 6 for bug 1622002

I don't want to revert the original fix because I don't think that gets us to a better place. With that fix in place, at least deployers have a chance of seeing from the sanity check that they need to update dnsmasq to a higher minimum version in order to use stateful IPv6. If they see it and update dnsmasq, then stateful IPv6 has a chance of working. If we revert then we have no chance of it working.

Ideally, from a end user's point of view, we'd generate an API error if the agents aren't going to be able to handle a stateful IPv6 subnet. So, I think we should work toward that. But, to accomplish that, we'll end up with a fix that cannot be backported to Newton, right?