Upstream: fixed $upstream_status when upstream returns 503/504.
Upstream: fixed $upstream_status when upstream returns 503/504.

If proxy_next_upstream includes http_503/http_504, and upstream
returns 503/504, $upstream_status converted this to 502 for any
values except the last one.

hy0kl/nginx,hy0kl/nginx,hy0kl/nginx