app.py: appended lora model of sdxl_lightning_2step_lora & sdxl_lightning_4step_lora.

app.py

@@ -118,7 +118,9 @@ LORA_MODELS = [
 	"ral-wtchz-sdxl_233487",
 	"sdxl_cute_social_comic-000002_107980",
 	"sdxl_glass_136034",
-	"sdxl_lightning_8step_lora_290441",
+	"sdxl_lightning_2step_lora",
+	"sdxl_lightning_4step_lora",
+	"sdxl_lightning_8step_lora",
 	"sdxl_offset_example_v10_113006",
 	"sdxl_wrong_lora",
 	"xl_more_art-full_v1_113467",
@@ -418,6 +420,9 @@ def generate_image (
 		)
 
 		print('task_id:', datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"), res.task.task_id)
+
+		if not hasattr(res, 'images_encoded'):
+			raise gr.Error(f'Error: {res.task}')
 	except Exception as e:
 		raise gr.Error(f'Error: {e}')