*) Feature: OpenSSL 3.0 compatibility.

*) Bugfix: SSL variables might be empty when used in logs; the bug had
   appeared in 1.19.5.

*) Bugfix: keepalive connections with gRPC backends might not be closed
   after receiving a GOAWAY frame.

*) Bugfix: backend SSL connections in the stream module might hang after
   an SSL handshake.

*) Bugfix: SSL connections with gRPC backends might hang if select,
   poll, or /dev/poll methods were used.

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

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