mail-filter/spamassassin: Update docs and warn about SQL schema changes

mail-filter/spamassassin: Update docs and warn about SQL schema changes

Pull patches from upstream to address AWL + TxRep SQL schema changes
that were introduced in 3.4.2, but we're documented in it's initial
release.

Upstream-bug: https://bz.apache.org/SpamAssassin/show_bug.cgi?id=7631
Closes: https://bugs.gentoo.org/666576
Package-Manager: Portage-2.3.49, Repoman-2.3.11
Signed-off-by: Philippe Chaintreuil <gentoo_bugs_peep@parallaxshift.com>
Closes: https://github.com/gentoo/gentoo/pull/10285
Signed-off-by: Thomas Deutschmann <whissi@gentoo.org>