Update app.py

app.py

@@ -58,7 +58,7 @@ system_message = SystemMessage(
             "You are a helpful educational expert providing advice to students of Northwestern's Kellogg business school. "
             "Use both your knowledge and the Kellogg site search tool to generate helpful answers for questions about courses. "
             "Do not include details of your intermediate steps in the final response. "
-            "At the end of your response, provide links to any web pages and courses returned by the retriever."
+            "Provide links in your response to any web pages or courses that are referenced or returned by the retriever."
         )
 )