stock_release_channel_shipment_advice_deliver: fix notification

Test if the shipment advice is linked to a release channel for sending notification

stock_release_channel_shipment_advice_deliver/models/shipment_advice.py

@@ -78,13 +78,15 @@ def _auto_process(self):
 
     def _postprocess_action_done(self):
         res = super()._postprocess_action_done()
+        if not self.release_channel_id:
+            return res
         if self.state == "error":
             return self.release_channel_id._shipment_advice_auto_process_notify_error(
                 self.error_message
             )
-        if self.state != "done":
-            return res
-        return self.release_channel_id._shipment_advice_auto_process_notify_success()
+        if self.state == "done":
+            return self.release_channel_id._shipment_advice_auto_process_notify_success()
+        return res
 
     def action_done(self):
         # If the channel is in error and we try to validate its shipment