Error polling issue

Previously we redirected to the atlassian-connect.json file in our app like below,

app.get('/', function (req, res) {
             // If the request content-type is text-html, it will decide which to serve up
             'text/html': function () {
             // This logic is here to make sure that the `atlassian-connect.json` is always
             // served up when requested by the host
             'application/json': function () {

And we realized accessing json file takes more time rather than writing the json in response directly. So, we have modified the code like this,

app.get('/', function (req, res) {
        res.writeHead(200, {"Content-Type": "application/json"});
		rres.write('{"key":"com.jira.addon.rqgantt","name":"Crystal Gantt","description":"Gantt Visualization for your Project for better Task and Resource Management","vendor":{"name":"RadiantQ","url":""},"apiVersion":2,"baseUrl":"","links":{"self":"","homepage":""},"authentication":{"type":"jwt"},"lifecycle":{"installed":"/installed","uninstalled":"/uninstalled"},"enableLicensing":true,"scopes":["READ","WRITE","DELETE","ADMIN"],"modules":{"generalPages":[{"key":"CrystalGanttAddon","location":"","name":{"value":"Crystal Gantt"},"url":"/Gantt","icon":{"width":80,"height":80,"url":""},"conditions":[{"condition":"user_is_logged_in"}]}]}}');

Now, we have modified the addon descriptor in marketplace to access our site directly. But, still we are getting an email for Error polling your descriptor with the content of accessing the file which is not used now.

Why the JIRA marketplace is still polling for atlassian-connect.json file which is not used now?

Thanks in advance.