This blocks disallowed extensions from probing
It also requires all available segments to have matching extensions to the format
mpegts is treated independent of the extension
It is recommended to set the whitelists correctly
instead of depending on extensions, but this should help a bit,
and this is easier to backport
Fixes: CVE-2023-6602 II. HLS Force TTY Demuxer
Fixes: CVE-2023-6602 IV. HLS XBIN Demuxer DoS Amplification
The other parts of CVE-2023-6602 have been fixed by prior commits
Found-by: Harvey Phillips of Amazon Element55 (element55)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>