Remove TLSv1 and TLSv1.1 from COMPATIBLE_TLS in 2020 (deferred)

[swankjesse]

Browser vendors announced they’re phasing out obsolete versions of TLS in March 2020.
https://blog.mozilla.org/security/2018/10/15/removing-old-versions-of-tls/

In early 2019 we demoted TLSv1 and TLSv1.1 from MODERN_TLS to COMPATIBLE_TLS.

In March 2020 we should remove them from COMPATIBLE_TLS. This will make it so these TLS versions are only available with a custom ConnectionSpec.

[yschimke]

Deferred because Coronavirus https://www.bleepingcomputer.com/news/security/firefox-reenables-insecure-tls-to-improve-access-to-covid19-info/

[yschimke]

Removed again https://hacks.mozilla.org/2020/02/its-the-boot-for-tls-1-0-and-tls-1-1/

[yschimke]

@swankjesse worth doing to 5.0?

[swankjesse]

Yep. I put this on the 5.0 milestone.

[yschimke]

Unfortunately this makes MODERN_TLS and COMPATIBLE_TLS identical. I guess incidentally common, they may drift in future.