I got the following unexpected response when trying to retrieve <http:https://upload.wikimedia.org/wikipedia/commons/8/8f/Flag_of_Estonia.svg>:
500 No Host option provided
If you made recent changes to your domain name (DNS) configuration, you may also want to check that your domain records are correct, or ask your hosting company to do so.