- update to 2.6.6
- amavisd-release was not sending a 'mail_file' attribute when a quarantined
message was a non-compressed file in a single-level directory quarantine
- quarantining to SQL was sporadically failing, reporting some unrelated
random error (like 'not available' or 'OpenSSL error: header too long');
- avoid a warning "_WARN: Use of uninitialized value in string eq at ...
line 275." when an SQL-based white/black-listing is used;
- wrap the sql clause SET NAMES 'utf8' so that only a warning at
a log level 2 is issued if an SQL server does not understand the
command (SQLite, old versions of MySQL) instead of aborting;

- when a back-end MTA rejected a message, amavisd would send a non-delivery
status notification, but also propagate the reject status back, which is
wrong, only one or the other response would be appropriate. A fix also
allows choosing either a D_REJECT, D_BOUNCE or D_DISCARD response for
such a case, configurable through %final_destiny_by_ccat at a CC_MTA
entry, defaulting to D_REJECT;