PHP 8.x - Replaced create_function with inline function

vtlib/thirdparty/network/Request.php

@@ -965,10 +965,11 @@ class HTTP_Request
 
             // "normal" POST request
             if (!isset($boundary)) {
-                $postdata = implode('&', array_map(
-                    create_function('$a', 'return $a[0] . \'=\' . $a[1];'),
-                    $this->_flattenArray('', $this->_postData)
-                ));
+                $callback = function_exists('create_function')?
+                create_function('$a', 'return $a[0] . \'=\' . $a[1];') :
+                function ($a) { return $a[0] .'='. $a[1]; };
+
+                $postdata = implode('&', array_map($callback, $this->_flattenArray('', $this->_postData)));
 
             // multipart request, probably with file uploads
             } else {