Catalog ordering “orderby” var was vulnerable to XSS

Official description: Check query var for orderby.

This vulnerability affects the following application versions:

• WooCommerce 3.3.0
• WooCommerce 3.3.0-rc.1
• WooCommerce 3.3.0-rc.2
• WooCommerce 3.3.1
• WooCommerce 3.3.1-rc.1
• WooCommerce 3.3.2
• WooCommerce 3.3.2-rc.1
• WooCommerce 3.3.3
• WooCommerce 3.3.4