Steps to reproduce the issue

The instructions says that "If empty 'label label-info' will be added by the default tag layout." But that isn't quite true as the field has a default value of 'label label-info' so even if left blank the default value will be saved. This default value is not needed because the layout will add it anyway
<?php $link_class = $tagParams->get('tag_link_class', 'label label-info'); ?> as correctly described in the tooltip.