Update lang.blade.php

resources/views/layouts/lang.blade.php

@@ -8,6 +8,7 @@
 {{-- Redirects to https if enabled in the advanced-config --}}
 @if(env('FORCE_ROUTE_HTTPS') == 'true')
 @php
+header("Content-Security-Policy: upgrade-insecure-requests");
 if (! isset($_SERVER['HTTPS']) or $_SERVER['HTTPS'] == 'off' ) {
     $redirect_url = "https://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
     header("Location: $redirect_url");