The certificates are misconfigured, you get the following error mesage:
ssl.CertificateError: hostname u'zdf-hdios-none-i.zdf.de' doesn't match either of 'a248.e.akamai.net', '*.akamaihd.net', '*.akamaihd-staging.net', '*.akamaized.net', '*.akamaized-staging.net'