fix(nginx.tmpl): set $cors to true so that the Access-Control-* headers will be added

Signed-off-by: Sjouke de Vries <info@sdvservices.nl>

rootfs/etc/nginx/template/nginx.tmpl

@@ -942,6 +942,7 @@ stream {
 
 {{/* CORS support from https://michielkalkman.com/snippets/nginx-cors-open-configuration.html */}}
 {{ define "CORS" }}
+     set $cors 'true';
      {{ $cors := .CorsConfig }}
      # Cors Preflight methods needs additional options and different Return Code
      {{ if $cors.CorsAllowOrigin }}