Correct help function output in docker config.

Previously the help function output in the docker config listed port 80
as the port on which the server would listen for DNS over UDP and TCP.
However that was inconsistent with the first output line where it was
indicated to be port 53. This has now been corrected.
31 jobs for docker-print_help
in 12 minutes and 20 seconds and was queued for 3 seconds