Here’s how I fixed it in Woocommerce version 2.5.2
1. Disable the lightbox, you’ll find this option in Woocommerce -> Settings -> Products Tab -> Display Link -> Very bottom checkbox
2. Edit the product-image.php in \plugins\woocommerce\templates\single-product
Change the line:
$image_link = wp_get_attachment_url( get_post_thumbnail_id() );
to
$image_link = esc_url( $product->get_product_url() );
Save and enjoy.