bpo-30714: ALPN changes for OpenSSL 1.1.0f (#2305)

OpenSSL 1.1.0 to 1.1.0e aborted the handshake when server and client
could not agree on a protocol using ALPN. OpenSSL 1.1.0f changed that.
The most recent version now behaves like OpenSSL 1.0.2 again. The ALPN
callback can pretend to not been set.

See https://github.com/openssl/openssl/pull/3158 for more details

Signed-off-by: Christian Heimes <christian@python.org>