Nginx [nginx-announce] nginx-1.21.6

Changes with nginx 1.21.6 25 Jan 2022

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*) Bugfix: when using EPOLLEXCLUSIVE on Linux client connections were
unevenly distributed among worker processes.

*) Bugfix: nginx returned the "Connection: keep-alive" header line in
responses during graceful shutdown of old worker processes.

*) Bugfix: in the "ssl_session_ticket_key" when using TLSv1.3.