Issue geerlingguy#1368: Fix private files not accessable with nginx

Author: oxyc

provisioning/templates/nginx-vhost.conf.j2

@@ -76,6 +76,9 @@ server {
  location ~ ^/sites/.*/files/styles/ {
  try_files $uri @rewrite;
  }
+ location ~ ^(/[a-z\-]+)?/system/files/ {
+ try_files $uri /index.php?$query_string;
+ }
  {% endblock %}
 
  {% block location_favicon -%}