With the latest versions of the linux packages, this should now be the same across all systems. Editing the /etc/default/openhab2 file with the lines:
OPENHAB_HTTP_PORT=9090
OPENHAB_HTTPS_PORT=9091
will change the appropriate ports. Thanks @ralle for pushing this fix.
If it still doesn’t work as expected for some, let me know and I will work to resolve it.