Replace app.html with dum_3D_slunce.html in index.php for updated content delivery

locenice2/index.php

@@ -1,10 +1,3 @@
 <?php
-// Upload this whole folder, not only this file. No Node.js or database required.
-header('Content-Type: text/html; charset=utf-8');
-header('X-Content-Type-Options: nosniff');
-$file = __DIR__ . '/app.html';
-if (!is_readable($file)) {
-    http_response_code(500);
-    exit('Chybi app.html. Nahrajte celou slozku locenice2.');
-}
-readfile($file);
+
+readfile(__DIR__ . '/dum_3D_slunce.html');