fix f-string error

app.py

@@ -58,11 +58,11 @@ if prompt := st.chat_input(placeholder="Write to ALOQAS..."):
         with st.sidebar:
             st.title("Statistics on the last answer")
             st.write(f"Score: {round(json.loads(response.text)['score'], 3)}")
-            st.write(f"Start: {json.loads(response.text)["start"]}")
-            st.write(f"End: {json.loads(response.text)["end"]}")
+            st.write(f"Start: {json.loads(response.text)['start']}")
+            st.write(f"End: {json.loads(response.text)['end']}")
 
 for msg in st.session_state.messages:
-    st.chat_message(msg["role"]).write(msg["content"])
+    st.chat_message(msg["role"]).write(msg['content'])
 
 if error == 1:
         message_rouge = "⚠️ Please provide a context via the menu on your left."