[9.0] [FIX] Mail Optional Follower Notification: populate needaction partners only with recipients

From commit 1665bc95ec in 10.0

mail_optional_follower_notification/models/mail_message.py

@@ -17,3 +17,13 @@ class MailMessage(models.Model):
             force_partners_to_notify = [d['id'] for d in partner_list]
             ctx['force_partners_to_notify'] = force_partners_to_notify
         return super(MailMessage, self.with_context(ctx)).create(values)
+
+    @api.multi
+    def _notify(self, force_send=False, user_signature=True):
+        res = super(MailMessage, self)._notify(
+            force_send=force_send, user_signature=user_signature)
+        if self.env.context.get('force_partners_to_notify'):
+            # Needaction only for recipients
+            self.needaction_partner_ids = [
+                (6, 0, self.env.context.get('force_partners_to_notify'))]
+        return res