Issue #3436692 - Fix spell

Related to #3436692

src/Routing/TrailingSlashUrlGenerator.php

@@ -72,7 +72,7 @@ class TrailingSlashUrlGenerator extends UrlGenerator {
   }
 
   /**
-   * Helper to get language perfix.
+   * Helper to get language prefix.
    */
   private function getLanguagePrefix($route_name, $options) {
     $language_options = $options;