Use FTL-provided fileversion() function

Signed-off-by: DL6ER <dl6er@dl6er.de>

scripts/pi-hole/php/func.php

@@ -112,20 +112,6 @@ function checkfile($filename)
     return '/dev/null';
 }
 
-// Avoid browser caching old versions of a file, using the last modification time
-//   Receive the file URL (without "/admin/");
-//   Return the string containin URL + "?v=xxx", where xxx is the last modified time of the file.
-function fileversion($url)
-{
-    $filename = $_SERVER['DOCUMENT_ROOT'].'/admin/'.$url;
-    $ver = 0;  // Default
-    if (file_exists($filename)) {
-        $ver = filemtime($filename);
-    }
-
-    return $url.'?v='.$ver;
-}
-
 // Credit: http://php.net/manual/en/function.hash-equals.php#119576
 if (!function_exists('hash_equals')) {
     function hash_equals($known_string, $user_string)