bugfix: add missing app var

app.py

@@ -3249,6 +3249,10 @@ streaming_ai_chatbot = gr.Chatbot(
     show_copy_button=True,
 )
 def create_app():
+
+    app = FastAPI()
+    app.add_middleware(BlockFileRedirectMiddleware)
+    
     with gr.Blocks(theme=gr.themes.Base(primary_hue=gr.themes.colors.orange, secondary_hue=gr.themes.colors.amber, text_size = gr.themes.sizes.text_lg), head=HEAD, js=JS, css=CSS) as demo:
         with gr.Row() as admin:
             password = gr.Textbox(label="Password", type="password", elem_id="password_input", visible=True)