Appointment+ Sends Email every time an Appointment is saved

It's sending out emails every time I change the appointment status.

Ash confirmed this issue and could replicate on his test site too in chat on 2nd August, 2017. Then he gave me the following fix:

Please go to /wp-content/plugins/appointments/includes/class-app-notifications-manager.php , Line no 53

After this line:
public function change_status( $app_id, $new_status, $old_status ) {

Put this:
if( is_admin() ) return;

He said he will forward this to developer.

Can you please review this and add in plugin core file so I don't have to manually do this every time the plugin updates?