Update app.js

@@ -103,8 +103,8 @@ async function handleEvent(event) {
         var text='';
         while(jsonResponse.indexOf('text\\')!=-1)
         {
-          data=data.substring(data.indexOf('text\\')+9);
-          text+=data.substring(0,data.indexOf("\\"))+" ";
+          jsonResponse=jsonResponse.substring(data.indexOf('text\\')+9);
+          text+=jsonResponse.substring(0,jsonResponse.indexOf("\\"))+" ";
         }
         console.log("text:"+text);
         var url="https://www.genie.co.kr/search/searchLyrics?query="+ encodeURI(text);