Update from 1.19.5 to 1.19.6.

<Changelog>

*) Bugfix: "no live upstreams" errors if a "server" inside "upstream"

block was marked as "down".

*) Bugfix: a segmentation fault might occur in a worker process if HTTPS

was used; the bug had appeared in 1.19.5.

*) Bugfix: nginx returned the 400 response on requests like

"GET http://example.com?args HTTP/1.0".

*) Bugfix: in the ngx_http_flv_module and ngx_http_mp4_module.

Thanks to Chris Newton.

</Changelog>