Add additional URL that was deployed some time ago

content-security-policy.php

@@ -86,6 +86,8 @@ $sites = array(
   '*.ads.linkedin.com',
   // Hootsuite Campaigns. RT#582824.
   '*.hscampaigns.com',
+  // Used by MSI, confirmed by Joe Kwan
+  'secure.adnxs.com',
 );
 while ($site = array_shift($sites)) {
   $items[] = 'https://' . $site;