Update WysiwygHelper.php

Hi, I'm getting 2 errors in CakePHP 2.3.

Strict (2048): Declaration of WysiwygHelper::input() should be compatible with WysiwygAppHelper::input($fieldName = NULL, $options = Array, $helperOptions = Array) [APP\Plugin\Wysiwyg\View\Helper\WysiwygHelper.php, line 15]

Strict (2048): Declaration of WysiwygHelper::textarea() should be compatible with WysiwygAppHelper::textarea($fieldName = NULL, $options = Array, $helperOptions = Array) [APP\Plugin\Wysiwyg\View\Helper\WysiwygHelper.php, line 15]