[zdf] Ignore hls manifests that use https (closes #8665)

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'

youtube_dl/extractor/zdf.py

@@ -137,6 +137,10 @@ class ZDFIE(InfoExtractor):
                 formats.extend(self._extract_smil_formats(
                     video_url, video_id, fatal=False))
             elif ext == 'm3u8':
+                # the certificates are misconfigured (see
+                # https://github.com/rg3/youtube-dl/issues/8665)
+                if video_url.startswith('https://'):
+                    continue
                 formats.extend(self._extract_m3u8_formats(
                     video_url, video_id, 'mp4', m3u8_id=format_id, fatal=False))
             elif ext == 'f4m':