app.py: reduce allowed concurrency

app.py

@@ -322,6 +322,6 @@ with gr.Blocks(css=css) as demo:
             send_to_txt2img_btn.click(send_to_txt2img, inputs=[image_input], outputs=[tabs, prompt, negative_prompt,
                                                                                       steps, seed, model, sampler,
                                                                                       width, height, cfg_scale],
-                                      concurrency_limit=64)
+                                      concurrency_limit=32)
 
-demo.queue(max_size=80, api_open=False).launch(max_threads=256, show_api=False)
+demo.queue(max_size=40, api_open=False).launch(max_threads=128, show_api=False)