bug in creating a group

Hey there,

This plugin looks awesome, but i get an error when i try to create a group 🙁

Warning: rtrim() expects parameter 1 to be string, array given in /home/tet/public_html/blog/wp-content/plugins/wp-post-status-notifications/wp_post_status_notifications.php on line 279

i-m using the latest 4.2.3 wp, and it has just a helpdesk plugin with a normal theme.

Customising who and when gets an email is what i need, and this plugin might work 🙂 if it didn`t had this bug.

Cheers.

https://ww.wp.xz.cn/plugins/wp-post-status-notifications/