That's the TCP port cupsd listens on. You want to look at the UDP port cups-browsed listens on (which is where the problem is, and it isn't configurable: if cups-browsed is running, you're probably vulnerable).

In general I would say don't look at config files to verify this kind of thing. Use something like 'ss -lp' to get a list of what processes on your machine are actually listening on (anything that isn't 127.0.0.* or [::1] is generally going to mean network-accessible)