Refactor app.py to fix bug in run_button click event handling

app.py

@@ -52,8 +52,8 @@ with gr.Blocks() as demo:
 
     run_button.click(
       fn=clear_output,
-      inputs=[output_slider]
-      outputs=output_slider
+      inputs=[output_slider],
+      outputs=[output_slider]
     ).then(
       upscale_image, 
       [input_image, resolution, num_inference_steps, strength, hdr, guidance_scale, controlnet_strength, scheduler_name],