*) Bugfix: nginx might hog CPU; the bug had appeared in 1.11.11.
Changes with nginx 1.11.11 (21 Mar 2017)
*) Feature: the "worker_shutdown_timeout" directive.
*) Feature: vim syntax highlighting scripts improvements.
Thanks to Wei-Ko Kao.
*) Bugfix: a segmentation fault might occur in a worker process if the
$limit_rate variable was set to an empty string.
*) Bugfix: the "proxy_cache_background_update",
"fastcgi_cache_background_update", "scgi_cache_background_update",
and "uwsgi_cache_background_update" directives might work incorrectly
if the "if" directive was used.
*) Bugfix: a segmentation fault might occur in a worker process if
number of large_client_header_buffers in a virtual server was
different from the one in the default server.
*) Bugfix: in the mail proxy server.
