M templates/security_tags.html →
templates/security_tags.html <!-- These tags are here for demostration. It's recommended to send them via HTTP headers instead. -->
-<meta http-equiv="Content-Security-Policy" content="default-src 'none'; img-src 'self'; object-src 'none'; script-src 'none'; style-src 'unsafe-inline'; frame-ancestors 'none'">
+<meta http-equiv="Content-Security-Policy" content="default-src 'none'; img-src 'self'; object-src 'none'; script-src 'none'; style-src 'unsafe-inline'">