Yii-Redactor placeholder text is added in db if empty

I am using Yii-Redactor for one of the text and if i don not change content in there it saves placeholder content in database.Code is as below.

echo $form->redactorControlGroup($lesson, 'long_description', [

			'buttons'           => [






















			'formattingTags'    => ['p', 'blockquote', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6'],

			'imageUpload'       => $this->createUrl('/media/upload'),

			'imageGetJson'      => $this->createUrl('/media/json'),

			'convertVideoLinks' => true,

			'placeholder' => 'e.g. sdj jfkdj dkfjkld kfjlkdjfkdjflkdjfkldjf ldkjflkdjfdklf kfjk sdfjkldjf kjfskljf sdlkjsdkf jdksfd',


It should not save placeholder content …

How can i do that ??