reuse keepalive connections if there are no free worker connections
patch by Maxim Dounin
diff --git a/src/core/ngx_cycle.h b/src/core/ngx_cycle.h
index d96c85f..e14983d 100644
--- a/src/core/ngx_cycle.h
+++ b/src/core/ngx_cycle.h
@@ -44,6 +44,8 @@
     ngx_connection_t         *free_connections;
     ngx_uint_t                free_connection_n;
 
+    ngx_queue_t               reusable_connections_queue;
+
     ngx_array_t               listening;
     ngx_array_t               pathes;
     ngx_list_t                open_files;