Hi,
That's a bug that you already fixed on our end and which will be patched in the next version.
If you don't want to wait, you can edit the file components/com_hikashop/controllers/product.php and change the lines (several occurrences):
if(strpos($url,HIKASHOP_LIVE)===false && preg_match('#^https?://.*#',$url)) return false;
to:
$url = str_replace(array('http://www.','https://www.'), array('http://','http://'),$url);
$live = str_replace(array('http://www.','https://www.'), array('http://','http://'),HIKASHOP_LIVE);
if(strpos($url,$live)!==0 && preg_match('#^https?://.*#',$url)) return false;