I see also that the base URL in your template is also with HTTP instead of HTTPS:
<base href="
openroadleatherandaccessories.com/
">
Sometimes, it comes from the url specified in the configuration file of joomla.
Please understand that this is not a HikaShop problem. You need to look at the HTML of your page with Firebug and look for the resources (images, javascript, CSS files) which are loaded with HTTP instead of HTTPS. Then, change them or remove them, and when you don't have any anymore it will validate.