Pinterest button with the post thumbnail – how to get rid of "rel="lightbox…

i am using a Pinterest button with the post thumbnail in “loop-index.php”

echo '<div class="pinterest-feature"><a aria-hidden="true" data-icon="" target="_blank" href="http://pinterest.com/pin/create/button/?url='.urlencode(get_permalink($the_id)).'&media='.$link.'"></a></div>';

that renders as

<div class="pinterest-feature"><a aria-hidden="true" data-icon="" target="_blank" href="http://pinterest.com/pin/create/button/?url=http%3A%2F%2Fdev.the-henry-journal.com%2Fdesign%2Flys-vintage%2F&media=http://dev.the-henry-journal.com/wp-content/uploads/2013/06/hamburg_lys-vintage_laden2.jpg" rel="lightbox[auto_group1]"></a></div>

how can I get rid of “rel=”lightbox[auto_group1]”

I tried “.avia_image_by_id(get_post_thumbnail_id(), ‘large’, ‘url’).”