MAGETWO-44005: Checkout with Paypal Express button becomes unavailable after...

MAGETWO-44005: Checkout with Paypal Express button becomes unavailable after changing quantity in Mini Shopping Cart

app/code/Magento/Checkout/view/frontend/web/js/view/minicart.js

@@ -72,6 +72,12 @@ define([
                 this.isLoading(addToCartCalls > 0);
                 sidebarInitialized = false;
                 initSidebar();
+
+                /**TODO: Extra options support. Should be refactored after MAGETWO-43159. */
+                setInterval(function(){
+                    minicart.trigger('contentUpdated');
+                }, 500);
+
             }, this);
             $('[data-block="minicart"]').on('contentLoading', function(event) {
                 addToCartCalls++;