Yes you're not connecting to the site with a secure connection, it's never been setup to use secure connections so per default it's insecure. Your browser is complaining that it's not using https (you can tell since we're using
http://www.juventuz.com, not
https://www.juventuz.com, check your browser url window) and because of that we don't have a SSL certificate for the site.
Since you're seeing this just now you must have changed your security settings somehow. It's nothing to worry about. Most likely you can whitelist the site so you don't see the warning. We might get a SSL certificate for the site in the future but it's not a top priority although it's not a bad idea.