Update SpokenLanguage.php

Changed 'iso_369_1' on line 28 to 'iso_639_1'.

Author: esbjorn

lib/Tmdb/Model/Common/SpokenLanguage.php

@@ -25,7 +25,7 @@ class SpokenLanguage extends AbstractModel implements LanguageFilter
     private $name;
 
     public static $properties = [
-        'iso_369_1',
+        'iso_639_1',
         'name',
     ];