MISP fails to start after upgrade

[fabrimagic72]

Hi,
i have upgraded my VPS with command apt-get dist-upgrade and after the upgrade procedure MISP is not running anymore.
it seems that apache2 has been upgraded and after the upgrade the apache daemon fails to start.
heres the output of the command docker logs misp

Starting supervisord...
2017-07-03 14:13:00,212 CRIT Supervisor running as root (no user in config file)
2017-07-03 14:13:00,220 INFO supervisord started with pid 1
2017-07-03 14:13:01,222 INFO spawnerr: can't find command '/usr/sbin/postfix'
2017-07-03 14:13:01,223 INFO spawned: 'resque' with pid 7
2017-07-03 14:13:01,224 INFO spawned: 'syslog-ng' with pid 8
2017-07-03 14:13:01,226 INFO spawned: 'apache2' with pid 9
2017-07-03 14:13:01,229 INFO spawned: 'cron' with pid 10
2017-07-03 14:13:01,237 INFO spawned: 'misp-modules' with pid 11
2017-07-03 14:13:01,246 INFO spawned: 'mysqld_safe' with pid 12
2017-07-03 14:13:01,255 INFO spawned: 'redis-server' with pid 13
2017-07-03 14:13:02,081 INFO success: resque entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
2017-07-03 14:13:02,081 INFO success: misp-modules entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
2017-07-03 14:13:02,082 INFO success: mysqld_safe entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
2017-07-03 14:13:02,223 INFO spawnerr: can't find command '/usr/sbin/postfix'
2017-07-03 14:13:02,507 INFO success: syslog-ng entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2017-07-03 14:13:02,507 INFO success: apache2 entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2017-07-03 14:13:02,507 INFO success: cron entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2017-07-03 14:13:02,507 INFO success: redis-server entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2017-07-03 14:13:02,564 INFO exited: apache2 (exit status 0; expected)
2017-07-03 14:13:04,300 INFO spawnerr: can't find command '/usr/sbin/postfix'
2017-07-03 14:13:06,131 INFO exited: misp-modules (exit status 1; not expected)
2017-07-03 14:13:06,236 INFO exited: resque (exit status 1; not expected)
2017-07-03 14:13:08,239 INFO spawnerr: can't find command '/usr/sbin/postfix'
2017-07-03 14:13:08,239 INFO gave up: master entered FATAL state, too many start retries too quickly

how can i investigate this?
Thanks in advance,
Fabrizio