Update app.py

app.py

@@ -130,7 +130,7 @@ with gr.Blocks(theme='SebastianBravo/simci_css') as demo:
 
 def apply_dark_theme(url):
     if not url.endswith('?__theme=dark'):
-        webbrowser.controller.open(url + '?__theme=dark')
+        webbrowser.open(url + '?__theme=dark')
 
 gradioURL = 'http://localhost:7860/'
 apply_dark_theme(gradioURL)