log a real response error code instead of "0"

src/http/ngx_http_request.c

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index fb00fc9..d37fead 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -1496,10 +1496,8 @@
         || rc == NGX_HTTP_REQUEST_TIME_OUT
         || r->connection->error)
     {
-        if (rc == NGX_HTTP_CLIENT_CLOSED_REQUEST
-            && r->headers_out.status == 0)
-        {
-            r->headers_out.status = NGX_HTTP_CLIENT_CLOSED_REQUEST;
+        if (rc > 0 && r->headers_out.status == 0) {
+            r->headers_out.status = rc;
         }
 
         if (ngx_http_post_action(r) == NGX_OK) {