update prompt of FORMAT_INSTRUCTIONS_3

app.py

@@ -846,7 +846,7 @@ When you don't have enough information, you can use tools and you must use the f
 If **Thought:**, **Action:**, **Action Input:** is missing in the response, you must re-write the response.
 
 ---
-When you need to provide final answer, you must use the following format to define **Final Answer:** after **Thought:**:
+When you are able to provide final answer, you must use the following format to define **Final Answer:** after **Thought:**:
 '''
 **Thought:** I now know the final answer|
 **Final Answer:** the final answer to the original input question|