turning off AUTH=CRAM-MD5

[David Wright]

Cyrus-imapd (1.6.24) insists on advertising AUTH=CRAM-MD5, even though 
this is a lie. This is (I think) one of the (many bad) side-effects of 
SASL -- because of SASL cyrus advertises this AUTH, but in fact my 
sasldb is utterly empty (all authentication is via PAM) and so any 
client that takes cyrus up on the offer gets told the user doesn't exist.

So... how can I get cyrus to stop advertising AUTH=CRAM-MD5?