* lisp/mh-e/mh-junk.el (mh-spamassassin-*list): Remove support
for SpamAssassin 2.20. (SpamAssassin 3.0 was released in 2004.)
This change updates both the flags for sa-learn and the comments
about how the current version works.
This change reverts part of a change made in 2003 that added
support for what was even then an "old version of spamassassin."