refactor: fix codebase consistency "wikipedia_language" => "en"

config.php.example

@@ -9,7 +9,7 @@
         "google_language_results" => "",
 
         // You can set a language for results in wikipedia
-        "wikipedia_language": "en",
+        "wikipedia_language" => "en",
 
         // You can use any Invidious instance here
         "invidious_instance_for_video_results" => "https://invidious.namazso.eu",