nginx-devel: updated to 1.19.1

Changes with nginx 1.19.1

*) Change: the "lingering_close", "lingering_time", and
  "lingering_timeout" directives now work when using HTTP/2.

*) Change: now extra data sent by a backend are always discarded.

*) Change: now after receiving a too short response from a FastCGI
  server nginx tries to send the available part of the response to the
  client, and then closes the client connection.

*) Change: now after receiving a response with incorrect length from a
  gRPC backend nginx stops response processing with an error.

*) Feature: the "min_free" parameter of the "proxy_cache_path",
  "fastcgi_cache_path", "scgi_cache_path", and "uwsgi_cache_path"
  directives.
  Thanks to Adam Bambuch.

*) Bugfix: nginx did not delete unix domain listen sockets during
  graceful shutdown on the SIGQUIT signal.

*) Bugfix: zero length UDP datagrams were not proxied.

*) Bugfix: proxying to uwsgi backends using SSL might not work.
  Thanks to Guanzhong Chen.

*) Bugfix: in error handling when using the "ssl_ocsp" directive.

*) Bugfix: on XFS and NFS file systems disk cache size might be
  calculated incorrectly.

*) Bugfix: "negative size buf in writer" alerts might appear in logs if
  a memcached server returned a malformed response.

(adam)