filesender: cronjob error DBIUsageException

Hi

I tried to upgrade to 2.8 because #557 is now fixed (big thx). But I run straight in the next issue.

What I did:

cd /data/www/filesender.mydomain.com/httpdocs
git fetch --all --tags
git checkout tags/filesender-2.8
chown -R webspace-user:webspace-user /data/www/filesender.mydomain.com/httpdocs
sudo -u webspace-user php /data/www/filesender.mydomain.com/httpdocs/scripts/upgrade/database.php
  ...
  All core code worked (leaving foreign keys), commit to database starting...
  Commit went well, those changes are now permanent
  Performing FOREIGN KEY creation...
  Everything went well
  Database structure is up to date

sudo -u webspace-user php /data/www/filesender.mydomain.com/httpdocs/scripts/task/cron.php
PHP Fatal error:  Uncaught DBIUsageException: database_access_failure in /data/www/filesender.mydomain.com/httpdocs/classes/utils/DBI.class.php:280
Stack trace:
#0 /data/www/filesender.mydomain.com/httpdocs/classes/data/AuditLog.class.php(430): DBI::__callStatic('exec', Array)
#1 /data/www/filesender.mydomain.com/httpdocs/scripts/task/cron.php(170): AuditLog::cleanup()
#2 {main}
  thrown in /data/www/filesender.mydomain.com/httpdocs/classes/utils/DBI.class.php on line 280

Did I something wrong on the upgrade, or is this the next cron bug?