Bug when rendering content_for_additional_checkout_buttons

Hi guys,

The liquid variable content_for_additional_checkout_buttons (rendered here: https://github.com/Shopify/Timber/blob/master/snippets/ajax-cart-template.liquid#L102) seems to be empty when the store has an empty cart.

Once the cart is populated with at least one item, then content_for_additional_checkout_buttons renders properly.

Test store: https://colors-theme-sections-demo-store.myshopify.com/

When the store is rendered with an empty cart, source code line 1699:
<div class="additional_checkout_buttons"></div>

When the store is rendered with a non empty cart, source code line 1699:
<div class="additional_checkout_buttons"><button name="goto_pp" type="submit" id="paypal-express-button" class="additional-checkout-button additional-checkout-button--paypal-express" value="paypal_express">Checkout with <img alt="PayPal" src="//cdn.shopify.com/s/assets/checkout/easy-checkout-btn-paypal-cadb680457a51ea1df32214b16adad91083c80679c7f5017e35c731832e59b90.png" /></button></div>