sinksmtp: improve another rule parsing error message

Once again the order in which we check for EOL versus other things is
important because 'thing is not a term' bubbles up aggressively.
sinksmtp: add rules helo-has options for various sorts of IP addresses

Now we can match against 'HELO [some.ip.address]' as well as whether the
given IP address is the local end, the remote end, or some other IP.