Cron logrotate warning: initctl: Unable to connect to Upstart

Hi people.
Debian 7 server updated recently from 12.0 Plesk to 12.5 Plesk. So far so good but...

We're having a email per day from Cron Daemon

Cron <root@hosting> test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )

/etc/cron.daily/logrotate:
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused

There's no other issue by now and all seems to be working properly.
Searched for cron jobs at /etc/cron.daily regarding...

Cron logrotate warning: initctl: Unable to connect to Upstart