Add nosniff header

adminer/include/design.inc.php

@@ -90,6 +90,7 @@ function page_headers() {
 	if ($adminer->headers()) {
 		header("X-Frame-Options: deny"); // ClickJacking protection in IE8, Safari 4, Chrome 2, Firefox 3.6.9
 		header("X-XSS-Protection: 0"); // prevents introducing XSS in IE8 by removing safe parts of the page
+		header("X-Content-Type-Options: nosniff");
 		header("Referrer-Policy: origin-when-cross-origin");
 	}
 }