MAGETWO-43934: Unnecessary loader on checkout when placing order with invalid credit card

- Fix on payflowpro

Author: Viktor Tymchynskyi

app/code/Magento/Paypal/view/frontend/web/js/view/payment/method-renderer/payflowpro-method.js

@@ -51,9 +51,8 @@ define(
             placeOrder: function () {
                 var self = this;
 
-                fullScreenLoader.startLoader();
-
                 if (this.validateHandler() && additionalValidators.validate()) {
+                    fullScreenLoader.startLoader();
                     this.isPlaceOrderActionAllowed(false);
                     $.when(setPaymentInformationAction(this.messageContainer, {
                         'method': self.getCode()