Fixed Slider Issue (retry)

[cookieshell]

Initial description that I wrote while trying to submit the commit: Fixed issue #23 that @HardeepAsrani mentioned in #23 and tried to fix in #24 but there was a github commit error.

Additional remark:

Tried to fix the issue @HardeepAsrani mentioned but apparently I also get some kind of github glitch that mentions 1 addition and 389 deletions but in fact there are a few lines (2-3) of code modified.

• The old book_rev_lite_wpr_get_product_image function was:

if(!function_exists("book_rev_lite_wpr_get_product_image")) {
        function book_rev_lite_wpr_get_product_image() {
            if(get_post_meta(get_the_ID(), 'cwp_rev_product_image', 'true')) {
                return get_post_meta(get_the_ID(), 'cwp_rev_product_image', true);
            } else {
                return get_theme_mod('default-product-image-upload');
            }
        }       
    }

• And the new one has a new elseif() that checks if the post has_post_thumbnail() or not.

if(!function_exists("book_rev_lite_wpr_get_product_image")) {
        function book_rev_lite_wpr_get_product_image() {
            if(get_post_meta(get_the_ID(), 'cwp_rev_product_image', 'true')) {
                return get_post_meta(get_the_ID(), 'cwp_rev_product_image', true);
            } elseif( has_post_thumbnail() ) {
                return wp_get_attachment_url(get_post_thumbnail_id($post->ID));
            } else {
                return get_theme_mod('default-product-image-upload');
            }
        }       
    }