little suggestion on class.attachment when saving

Hi jonathan,
Just a little suggestion for avoiding to store data in postmeta table when there is no attachments on a post :

in class.attachments.php line 1144 add something like this before saving :

if  (empty($attachments)){
   return $post_id;
} else {
// we're going to store JSON (JSON_UNESCAPED_UNICODE is PHP 5.4+)
$attachments = version_compare( PHP_VERSION, '5.4.0', '>=' ) ? json_encode( $attachments, JSON_UNESCAPED_UNICODE ) : json_encode( $attachments );
}

thanks a lot for your work

http://wordpress.org/extend/plugins/attachments/