r/v-m-nginx: Prevent requesting reload

Remote systems should not be able to trigger a reload of the services
behind the reverse proxy.

roles/victoria-metrics-nginx/templates/victoria-metrics.nginx.conf.j2

@@ -7,6 +7,10 @@ server {
         proxy_pass http://[::1]:8428/;
         client_max_body_size 100m;
     }
+
+    location ~ /-/reload {
+        deny all;
+    }
 {% for item in vm_nginx_proxy_paths %}
 
     location {{ item.path }} {