Bug#437405: this bug/#437405 - removed /etc/default/aumix by hand
It seems that /etc/default/aumix was included in very old
(pre-oldstable) aumix packages, but not current ones. Ideally, the
version of aumix that dropped the conffile would have removed it,
conditionally on its checksum matching the unmodified value, or moved
it out of the way, if its checksum didn't match.
Nowadays, dpkg has built-in support for "obsolete" conffiles, so I
think it's too late to add support anyway. Is there a .deb available
somewhere that shows that it was an included "conffile"?