The site is back up now, at a new IP address. It will take a while for DNS records to propogate.
If you can't get in using the regular address, try this instead:
https://54.217.248.250/That should work until DNS catches up.
Edit: it will show a warning about the URL not matching the certificate. So long as it says "the site identifies itself as just-dice.com" then you should be good.