Error accepting/declining an event

[jonzl]

Hi,
when I receive an event invitation and I click on accept, I get the following stacktrace in the error log.

16-Oct-2016 19:38:57 UTC] PHP Fatal error: Uncaught Error: Call to undefined method rcube_imap::set_mailbox() in /var/www/vhosts/xyz.de/httpdocs/roundcube/plugins/libcalendaring/libcalendaring.php:1364
Stack trace:

0 /var/www/vhosts/xyz.de/httpdocs/roundcube/plugins/calendar/calendar.php(3039): libcalendaring->mail_get_itip_object('INBOX', '8410', '3:0', 'event')

1 /var/www/vhosts/xyz.de/httpdocs/roundcube/program/lib/Roundcube/rcube_plugin_api.php(491): calendar->mail_import_itip()

2 /var/www/vhosts/jprior.de/httpdocs/roundcube/index.php(283): rcube_plugin_api->exec_action('calendar.mailim...')

3 {main}

thrown in /var/www/vhosts/xyz.de/httpdocs/roundcube/plugins/libcalendaring/libcalendaring.php on line 1364

I am using the latest Roundcube 1.2.2 on a PHP7 backend.
Any ideas to solve this error?

[HuidaeCho]

Pull request #7 should fix this set_mailbox error.