Update using_supervisord.md
Update using_supervisord.md

Fix factual error

change made by: GennadySpb <lipenkov@gmail.com>

Signed-off-by: Sven Dowideit <6f6969dc7db01e7204496bfb27e43d63ec4b2eb3@docker.com>

AdamOssenford/docker-pi,josemonsalve2/docker,carlye566/docker_eric,ClusterHQ/docker-plugins,seanmcdaniel/docker,carlye566/docker_eric,carlye566/docker_eric,ClusterHQ/docker-plugins,AdamOssenford/docker-pi,seanmcdaniel/docker,AdamOssenford/docker-pi,josemonsalve2/docker,ClusterHQ/docker-plugins,josemonsalve2/docker,seanmcdaniel/docker