Issue #3348569 by lauriii: Update UN official language list source

(cherry picked from commit b97fb783)

core/lib/Drupal/Core/Language/LanguageManager.php

@@ -338,9 +338,8 @@ public static function getStandardLanguageList() {
   /**
    * The 6 official languages used at the United Nations.
    *
-   * This list is based on
-   * http://www.un.org/en/sections/about-un/official-languages/index.html and it
-   * uses the same format as getStandardLanguageList().
+   * This list is based on https://www.un.org/en/our-work/official-languages
+   * and it uses the same format as getStandardLanguageList().
    *
    * @return array
    *   An array with language codes as keys, and English and native language