Log Message:
cyrus-sasl: Remove some outdated text from MESSAGE.

Some users found this text confusing and ended up trying to put config
files in the very directory we were telling them not to, e.g.
https://github.com/TritonDataCenter/pkgsrc/issues/378.

This text was added almost 7 years ago, so we can be pretty confident that
users have migrated past this change by now.