apache2 listen ports are now in a separate file

in apache2 the server listen ports are now in a separate file so to add a site on port :8000 you need to add 8000 to /etc/apache2/ports.conf AND add a <VirtualHost *:8000> to  yoursite.conf

# If you just change the port or add more ports here, you will likely also
# have to change the VirtualHost statement in
# /etc/apache2/sites-enabled/000-default.conf
Listen 80
Listen 8000