www/nginx-devel: update from 1.21.3 to 1.21.4.

New kernel TLS feature is available starting with FreeBSD 13.0,
and it requires OpenSSL 3.0, compiled with "enable-ktls" option.
Further, KTLS needs to be enabled in kernel, and in OpenSSL,
either via OpenSSL configuration file or with

ssl_conf_command Options KTLS;

in nginx configuration.

To enable kernel TLS on FreeBSD 13 and above:

1. kldload ktls_ocf
2. sysctl kern.ipc.tls.enable=1

to load a software backend, see man ktls(4) for details.

Also, please visit the following link to get more details
https://hg.nginx.org/nginx/rev/65946a191197

<Changelog>

*) Change: support for NPN instead of ALPN to establish HTTP/2

connections has been removed.

*) Change: now nginx rejects SSL connections if ALPN is used by the

client, but no supported protocols can be negotiated.

*) Change: the default value of the "sendfile_max_chunk" directive was

changed to 2 megabytes.

*) Feature: the "proxy_half_close" directive in the stream module.

*) Feature: the "ssl_alpn" directive in the stream module.

*) Feature: the $ssl_alpn_protocol variable.

*) Feature: support for SSL_sendfile() when using OpenSSL 3.0.

*) Feature: the "mp4_start_key_frame" directive in the

ngx_http_mp4_module.
Thanks to Tracey Jaquith.

*) Bugfix: in the $content_length variable when using chunked transfer

encoding.

*) Bugfix: after receiving a response with incorrect length from a

proxied backend nginx might nevertheless cache the connection.
Thanks to Awdhesh Mathpal.

*) Bugfix: invalid headers from backends were logged at the "info" level

instead of "error"; the bug had appeared in 1.21.1.

*) Bugfix: requests might hang when using HTTP/2 and the "aio_write"

directive.

</Changelog>