Update app_gradio.py

Minor typo correction

app_gradio.py

@@ -40,7 +40,7 @@ app = gr.Interface(
         gr.HTML(label="Source Documents")],  # FIXME: the label is not showing
     examples=[
         ["Is Joe Biden offering motel stays to undocumented immigrants?"],
-        ["Did Justin Trudeau sits in protest in support of the protesting Indian farmers?"],
+        ["Did Justin Trudeau sit in protest in support of the protesting Indian farmers?"],
     ])
 
 if __name__ == "__main__":