firewall blocks access to keyserver.ubuntu.com
firewall blocks access to keyserver.ubuntu.com

some firewalls block the access to the keyserver because of port 11371. With this patch port 80 will be used.
korczis/docker-squid-rubygems-proxy,zultron/docker-provisioning,sameersbn/docker-squid,opendoor-labs/docker-squid-s3,maqsoodumt/docker-squid,linearregression/docker-squid-s3,korczis/docker-squid-rubygems-proxy,boliu83/docker-squid,Optibus/docker-squid