I have put the correct mysql connections into the fogsettings file.
The fogsettings file is only used by the installer. Did you re-run the FOG installer after adjusting fogsettings? Or you can manually edit /var/www/html/fog/lib/fog/config.class.php for the DB settings.
The URL called is http://fog.server.ip/fog/status/kernelvers.php - be aware that this URL is called from your FOG master node. So if you can open this URL from your browser it doesn’t necessarily mean that it does work when called from the master node as well.