Add back in voila.json

voila.json

@@ -1,6 +1,11 @@
 {
   "Voila": {
     "ip":"0.0.0.0",
-    "port": 7860
+    "port": 7860,
+    "tornado_settings": {
+      "headers": {
+        "Content-Security-Policy": "frame-ancestors self *"
+      }
+    }
   }
 }