Firefox and sites on port 23

Problem:
"This address (%address) specifies a network port which is normally used for purposes other than Web browsing. Firefox has canceled the request for your protection."

If you open up a site located on certain port(s) not normally used for web browsing firefox stops you from going there FOR YOUR PROTECTION

Solution:
The correct workaround is adding a new string value to
about:config
called
network.security.ports.banned.override
Then enter a comma-separated list of port numbers to allow.