set "Content-Length: 0" for errors handled by "return 204"
diff --git a/src/http/ngx_http_request.h b/src/http/ngx_http_request.h
index b9ad2b5..08ccd13 100644
--- a/src/http/ngx_http_request.h
+++ b/src/http/ngx_http_request.h
@@ -430,6 +430,7 @@
     unsigned                          plain_http:1;
     unsigned                          chunked:1;
     unsigned                          header_only:1;
+    unsigned                          zero_body:1;
     unsigned                          keepalive:1;
     unsigned                          lingering_close:1;
     unsigned                          discard_body:1;