Feature request: remove hardcoded webui port from sabnzbd.sh

[perkmi]

For various reasons you may care about the webui port being used inside the docker container. sabnzbd.sh uses a hardcoded 8080. This could be achieved with an envioronment variable, or by reading the port number from sabnzbd.ini with the command "sed -n '/host = 0.0.0.0/{n;s/^port = //p;}' /config/sabnzbd.ini"

Not a huge deal, just a "would be nice" if you care and/or have the time. Thanks for everything you do!