Update app.js

@@ -129,7 +129,8 @@ async function handleEvent(event) {
                 resultm+=songList[i].singer+", "+songList[i].song+"\n";
               }
             }
-            client.replyMessage(event.replyToken,resultm).then(resolve).catch(reject);
+            var result = { type: 'text', text:resultm};
+            client.replyMessage(event.replyToken,result).then(resolve).catch(reject);
 
           });
         });