suggested sa install notes update: turn off iptables

[Trever Furnish]

I'm sure this is something I would have been aware of if I weren't doing
an initial, crash-through-it-as-fast-as-possible install of MailScanner
+ SpamAssassin and had actually take the time to properly understand
spamassassin, but that's what I'm doing, so...

Make test for spamassassin (at least the 'stable' version, 2.55), will
fail if the system is sufficiently locked down with iptables or
ipchains.  The initial spamc test takes a long, long time, then the
spamc_B test fails with "Not found: spamflag = X-Spam-Flag: YES", then
the spamc_c test hangs, then... well then I got bored and killed it, so
I dunno.

But /sbin/iptables/stop allows the tests to complete.  Guess now I'm
going to have to actually go read up on spamassassin to see what the
heck it needs. :-)

But it might be useful for you to add a note suggesting the reader turn
off iptables/ipchains in the install guide located here:

http://www.sng.ecs.soton.ac.uk/mailscanner/install/spamassassin.shtml

-t.