File Integrity Check recommends deletion of PiwikTracker.php

Recently I upgraded Matomo to version 3.6.0 After the upgrade it shows the following errors in File Integrity Check -

Files were found in your Matomo but we didn’t expect them.
–> Please delete these files to prevent errors. <–

File to delete: PiwikTracker.php
File to delete: misc/others/api_internal_call.php
File to delete: vendor/davaxi/sparkline/autoload.php
File to delete: vendor/davaxi/sparkline/src/autoload.php
File to delete: vendor/piwik/device-detector/autoload.php

To delete all these files at once, you can run this command:
rm “***/PiwikTracker.php” “***/misc/others/api_internal_call.php” “***/vendor/davaxi/sparkline/autoload.php” “***/vendor/davaxi/sparkline/src/autoload.php” “***/vendor/piwik/device-detector/autoload.php”

It looks like the files are essential files. Also, I am unable to change anything in website settings. It shows “Forbidden”, though I am not sure whether these two errors are related. Can anyone please help ?