[Dovecot] Use events to kill supervisord when main proc dies

[Postfix] Use events to kill supervisord when main proc dies
[SOGo] Use events to kill supervisord when main proc dies

data/Dockerfiles/postfix/supervisord.conf

@@ -13,3 +13,7 @@ autostart=true
 [program:postfix]
 command=/opt/postfix.sh
 autorestart=true
+
+[eventlistener:processes]
+command=/usr/local/sbin/stop-supervisor.sh
+events=PROCESS_STATE_STOPPED, PROCESS_STATE_EXITED, PROCESS_STATE_FATAL