fix a bug

Rodin.py

@@ -147,7 +147,11 @@ class Generator:
             return prompt, processed_image
         log("INFO", "Preprocessing image...")
         success = False
+        try_times = 0
         while not success:
+            if try_times > 3:
+                raise gr.Error("Failed to preprocess image")
+            try_times += 1    
             image_file = load_image(image_path)
             log("INFO", "Image loaded, processing...")
             if prompt and task_uuid: