WooCommerce: Remove "sort by price"

Hey guys,

i am really confuse right now.
I have tried to remove the Sort by price option, with

// Edit WooCommerce dropdown menu item of shop page//
// Options: menu_order, popularity, rating, date, price, price-desc
 
function rsd_catalog_orderby( $orderby ) {
    unset($orderby["price"]);
    unset($orderby["price-desc"]);
    return $orderby;
}
add_filter( "woocommerce_catalog_orderby", "rsd_catalog_orderby", 20 );

but it does not work.

However, it works with Storefront Theme, so Enfold is not calling the filter?
How can I get this working?
Thanks in advance.

Currently I have WooCommerce 2.6.11 isntalled.
(Booster for Woocommerce 2.5.9 | Booster Plus 1.1.0 installed too)