Bug#728339: plain/login authentication failure - no mechanism available

[Christian Schwamborn]

I would like to reopen this issue, as it is still not completely 
resolved, even in stretch / current sasl from git.

A 'normal' authentication works, but proxy authentication is broken 
since wheezy, as long as sasl has no auxprop module configured.

The current workaround is to configure any auxprop module, even if the 
backend (i.e. sasldb - easiest to configure) provides no authentication 
results.

The latest discussion on this topic I could find, points out, that there 
is still some unresolved issue in cyrus sasl:
https://lists.andrew.cmu.edu/pipermail/info-cyrus/2016-November/039241.html