adds csp header for frag.jetzt

nginx.conf

@@ -11,6 +11,7 @@ server {
       root /usr/share/nginx/html;
       index index.html index.htm;
       try_files $uri $uri/ /index.html =404;
+      add_header Content-Security-Policy frame-ancestors 'self' frag.jetzt staging.frag.jetzt;
 
       location ~ ^\/ngsw(-worker)?\.js(on)?.*$ {
          add_header Last-Modified $date_gmt;