Fix: docker can't kill errant subshell processes created by | pipe cmd.
Fix: docker can't kill errant subshell processes created by | pipe cmd.

dreamcat4/docker-images,dreamcat4/tvheadend-build,dreamcat4/docker-images,dreamcat4/docker-images,dreamcat4/docker-images,snowygoose/docker-images,tvheadend/tvheadend-build,tvheadend/tvheadend-build