Update app.py

app.py

@@ -14,7 +14,7 @@ image = Image.open('logo.png')
 st.image(image)
 
 if "openai_model" not in st.session_state:
-    st.session_state["openai_model"] = "gpt-3.5-turbo"
+    st.session_state["openai_model"] = "gpt-4o-mini"
 
 if "messages" not in st.session_state:
     st.session_state.messages = []