CSP: allow youtube as frame source in XL
diff --git a/data/kalamar-xl.conf b/data/kalamar-xl.conf
index d219b4b..272a806 100644
--- a/data/kalamar-xl.conf
+++ b/data/kalamar-xl.conf
@@ -42,7 +42,7 @@
     }],
   },
   CSP => {
-    'frame-src' => 'self',
+    'frame-src' => ['self', 'https://www.youtube.com'],
     'frame-ancestors' => ['self','http://korap.dnb.de/','https://korap.dnb.de/']
    },
  'Kalamar-Plugins' => {