Modules compatibility: additional upstream metrics.

src/http/ngx_http_upstream.h

diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index 3e714e5..56b54d1 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -61,6 +61,7 @@
     ngx_msec_t                       response_time;
     ngx_msec_t                       connect_time;
     ngx_msec_t                       header_time;
+    ngx_msec_t                       queue_time;
     off_t                            response_length;
     off_t                            bytes_received;