[ticket/14247] Use quotes around @ and % strings in YAML

PHPBB3-14247

phpBB/config/default/container/services_language.yml

@@ -2,21 +2,21 @@ services:
     language.helper.language_file:
         class: phpbb\language\language_file_helper
         arguments:
-            - %core.root_path%
+            - '%core.root_path%'
 
     language:
         class: phpbb\language\language
         arguments:
-            - @language.loader
+            - '@language.loader'
 
     language.loader_abstract:
         abstract: true
         class: phpbb\language\language_file_loader
         arguments:
-            - %core.root_path%
-            - %core.php_ext%
+            - '%core.root_path%'
+            - '%core.php_ext%'
 
     language.loader:
         parent: language.loader_abstract
         calls:
-            - [set_extension_manager, ["@ext.manager"]]
+            - [set_extension_manager, ['@ext.manager']]