Log Message:
nginx-devel: updated to 1.15.7

Changes with nginx 1.15.7:
*) Feature: the "proxy_requests" directive in the stream module.
*) Feature: the "delay" parameter of the "limit_req" directive.
*) Bugfix: memory leak on errors during reconfiguration.
*) Bugfix: in the $upstream_response_time, $upstream_connect_time, and
   $upstream_header_time variables.
*) Bugfix: a segmentation fault might occur in a worker process if the
   ngx_http_mp4_module was used on 32-bit platforms.