Bug in search results with products with variants

-- HikaShop version -- : 3.5.1
-- Joomla version -- : 3.8.12
-- PHP version -- : 7.1
-- Browser(s) name and version -- : All
-- Error-message(debug-mod must be tuned on) -- : Bug in search results with products with variants

Hello,

If you use the search to find products, and you are looking for a product that have variants, the main product will be shown in the search results. And if you click in the link of the main product, the main product will be shown the with free label (no price).
It was better, to avoid conflicts, if main products without price don't be showed in search results or if the link redirects user to a variant with price.