Unless the server is started as the root user, no ports numbered below 1025 can be used.
Either start the server as root, or modify your configuration file to have the server listen on 8443 instead of 443 (or any other number above 1024).
For instance, instead of
set httpsport 443
use
set httpsport 8443
This should fix the problem you are seeing - take heart, it's almost working!