Code review comment for lp://staging/~clint-fewbar/pyjuju/ec2-use-ip-address

I'm less interested in pursuing this approach now that I have tinkered with it. This makes the ec2 provider less robust without good cause. I think a better approach, such as a setting "use-ip" would be more appropriate for those rare private EC2 clouds that won't have resolvable dns. For common private openstack clouds, the native openstack provider makes more sense.