Feature: the “proxy_socket_keepalive”, “fastcgi_socket_keepalive”,”grpc_socket_keepalive”, “memcached_socket_keepalive”, “scgi_socket_keepalive”, and “uwsgi_socket_keepalive” directives.
Bugfix: if nginx was built with OpenSSL 1.1.0 and used with OpenSSL 1.1.1, the TLS 1.3 protocol was always enabled.