Upstream: updated list of ngx_event_connect_peer() return values.
Upstream: updated list of ngx_event_connect_peer() return values.

ngx_http_upstream_get_keepalive_peer() may return NGX_DONE to
indicate that the cached keepalive connection is reused.

hy0kl/nginx,firebase/nginx,firebase/nginx,firebase/nginx,firebase/nginx,hy0kl/nginx,hy0kl/nginx