Update app.py

app.py

@@ -95,7 +95,7 @@ def remove_message(position):
 # Display chat messages from history on app rerun
 pos = 0
 for message in st.session_state.messages:
-    pos++
+    pos=+1
     with st.chat_message(message["role"]):
         cols = st.columns([9,1])
         cols[1].markdown(message["content"])