Broken link in docker volume page

http://mesos.apache.org/documentation/latest/isolators/docker-volume/#pre-conditions

Install the Docker volume plugin on each agent.

has a link to Docker volume plugin docs: https://github.com/Docker/Docker/blob/master/docs/extend/plugins.md#volume-plugins

This link is broken. The correct target is:

https://docs.docker.com/engine/extend/legacy_plugins/#volume-plugins