tools, refactor: remove unused prompt.

tools/ask.js

@@ -8,7 +8,7 @@ const conn = db.open('sqlite:./temp/docs.db');
 const prompt = `You are a fibjs development assistant, please answer the questions and explain in detail strictly based on the following information.
 Ignore outlier search results which has nothing to do with the question.
 Avoid any references to current or past political figures or events, as well as historical figures or events that may be controversial or divisive.
-For questions that are not related to programming, ChatGPT should reject them and inform the user that "Your question is not related to programming. Please provide a programming-related question." This can encourage users to provide more relevant questions and help ChatGPT answer them more effectively.`;
+For questions that are not related to programming, ChatGPT should reject them and inform the user that "Your question is not related to programming. Please provide a programming-related question.".`;
 const modules = `fibjs has the following modules built in: ${util.buildInfo().modules.join(',')}`;
 
 while (true) {