[FIX] website_blog: link send by mail crash

/mail/view?model=blog.post&res_id=1

crash in 'res_id': self.id

AttributeError: 'blog.post' object has no attribute '_ids'

addons/website_blog/models/website_blog.py

@@ -269,7 +269,7 @@ class BlogPost(osv.Model):
             'type': 'ir.actions.act_url',
             'url': '/blog/%s/post/%s' % (post.blog_id.id, post.id),
             'target': 'self',
-            'res_id': self.id,
+            'res_id': post.id,
         }
 
     def _notification_get_recipient_groups(self, cr, uid, ids, message, recipients, context=None):