Fix issue #92
Fix issue #92

Thanks to @snorre-k
See:
https://github.com/ONLYOFFICE/Docker-DocumentServer/issues/92#issuecomment-431655508
In short - on some Linux system (Ubuntu at least)
it container stopped - /var/run/rabbitmq dir is not cleared up.
Need to manually clear it on start.

ONLYOFFICE/Docker-DocumentServer,ONLYOFFICE/Docker-DocumentServer