NetworkSettings.IPAddress field is deprecated in Docker

The latest docker API deprecates the NetworkSettings.IPAddress field, in favor of the NetworkSettings.Networks field.

https://docs.docker.com/engine/reference/api/docker_remote_api/#v1-21-api-changes

With this deprecation, NetworkSettings.IPAddress is not populated for containers running with networks that use new network plugins.

As a result the mesos API has no data in container_status.network_infos.ip_address or container_status.network_infos.ipaddresses.

The immediate impact of this is that mesos-dns is unable to retrieve a containers IP from the netinfo interface.