Update Japanese translation

Signed-off-by: Takashi SHIRAI <shirai@nintendo.co.jp>

plugins/enum-option.php

@@ -38,5 +38,6 @@ class AdminerEnumOption extends Adminer\Plugin {
 		'de' => array('' => 'Verwenden Sie <select><option> für die enum-Bearbeitung anstelle von <input type="radio">'),
 		'pl' => array('' => 'Użyj <select><option> do edycji enum zamiast <input type="radio">'),
 		'ro' => array('' => 'Utilizați <select><option> pentru editarea enum în loc de <input type="radio">.'),
+		'ja' => array('' => '列挙型の編集に <input type="radio"> ではなく <select><option> を使用'),
 	);
 }