Relay generates "open //./pipe/docker_engine: All pipe instances are busy." errors

When running docker-compose commands, which opens several simultaneous sockets at once, the relay generates error messages: ``` 2019/06/14 08:51:50 open //./pipe/docker_engine: All pipe instances are busy. ``` On the docker-compose side, this shows itself in several ways, but mostly seen as: ``` ERROR: for my-service ('Connection aborted.', BadStatusLine('No status line received - the server has closed the connection',)) ERROR: Couldn't connect to Docker daemon at http+docker://localunixsocket - is it running? ```