The check fails with the following error for some time:
broken https://www.gnu.org/software/libidn/#libidn2 - HTTPSConnectionPool(host='www.gnu.org', port=443): Max retries exceeded with url: /software/libidn/ (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7f5bd4c14590>: Failed to establish a new connection: [Errno 111] Connection refused'))
"https://www.dnssec-or-not.com/",
"https://www.flaticon.com/",
"https://www.freepik.com/",
+ "https://www.gnu.org",
"https://www.godaddy.com",
"https://www.icann.org",
]