Bug in combination with Polylang for WooCommerce

Hallo,

when you update an order from on-hold to completed via the order detail page in the backend a fatal error occurs and you see the email content on the page.

The plugin Polylang for WooCommerce calls the function WC_Payment_Gateways->get_available_payment_gateways() while creating the email.
And in your plugin the is_available() function try to get the cart total, but at that moment WC()->cart is null.

Best regards
Andi