Remove `is_countable` polyfill from install.php

see a178c052b8ecc5b1306607955702d6acf2ac254e

diff --git a/wcfsetup/install.php b/wcfsetup/install.php
index 47c700e89b917f30f52374e4e99f0283d9c259cb..37ae0196c04c59eae8095b325b93f8bfa5def8bf 100644 (file)
--- a/wcfsetup/install.php
+++ b/wcfsetup/install.php
@@ -517,10 +517,6 @@ function handleError($errorNo, $message, $filename, $lineNo) {
        throw new SystemException('PHP '.$type.' in file '.$filename.' ('.$lineNo.'): '.$message, 0);
 }
 
-if (!function_exists('is_countable')) {
-       function is_countable($var) { return is_array($var) || $var instanceof Countable || $var instanceof ResourceBundle || $var instanceof SimpleXmlElement; }
-}
-
 /** @noinspection PhpMultipleClassesDeclarationsInOneFile */
 /**
  * BasicFileUtil contains file-related functions.