Add default value for $ver in func.php

Signed-off-by: Christian König <ckoenig@posteo.de>

Co-authored-by: ElectronicsTinkerer <ElectronicsTinkerer@users.noreply.github.com>

scripts/pi-hole/php/func.php

@@ -117,6 +117,7 @@ function checkfile($filename)
 function fileversion($url)
 {
     $filename = $_SERVER['DOCUMENT_ROOT'].'/admin/'.$url;
+    $ver = 0;  // Default
     if (file_exists($filename)) {
         $ver = filemtime($filename);
     }