[FIX] mass_mailing: mail_thread model redefined as a osv.Model, while the...

[FIX] mass_mailing: mail_thread model redefined as a osv.Model, while the original mail thread is an AbstractModel. Mass mailing mail thread must be an Abstract Model as well

bzr revid: dle@openerp.com-20140414090825-o456mdd9q38m47mw

addons/mass_mailing/mail_thread.py

@@ -29,7 +29,7 @@ from openerp.osv import osv
 _logger = logging.getLogger(__name__)
 
 
-class MailThread(osv.Model):
+class MailThread(osv.AbstractModel):
     """ Update MailThread to add the feature of bounced emails and replied emails
     in message_process. """
     _name = 'mail.thread'