if only one worker, use it everywhere

templates/nginx.conf

@@ -66,7 +66,7 @@ http {
 	# sticky only on commercial nginx
         # sticky cookie srv_id expires=8h;
 {% for n in range(osp_worker_count) %}
-{% if n != 0 %}
+{% if n != 0 or osp_worker_count == 1 %}
         server 127.0.0.1:{{ osp_worker_start_port + n }};
 {% endif %}
 {% endfor %}