Update app.py

app.py

@@ -81,7 +81,7 @@ def handle_userinput(user_question):
 
     st.session_state.retrieved_text = response['source_documents'][0]
 
-    for i, (message, text) in enumerate(zip(st.session_state.chat_history, st.session_state.retrieved_text):
+    for i, (message, text) in enumerate(zip(st.session_state.chat_history, st.session_state.retrieved_text)):
         if i % 2 == 0:
             st.write(user_template.replace(
                 "{{MSG}}", message.content), unsafe_allow_html=True)