undo an invalid CSP change

lib/defaults.js

@@ -18,7 +18,7 @@ Default.commonCSP = function (domain, sandbox) {
          */
         "child-src 'self' blob: " + domain + sandbox,
         // IE/Edge
-        `frame-src 'self' blob:${sandbox}/* blob:${domain}/* ${domain} ${sandbox}`,
+        "'frame-src 'self' blob: " + sandbox,
 
         /*  this allows connections over secure or insecure websockets
             if you are deploying to production, you'll probably want to remove