PayPal: Only the frist refund was accepted by PayPal

(cherry picked from commit 7f6905c)

src/Smartstore.Modules/Smartstore.PayPal/Client/PayPalHttpClient.cs

@@ -343,8 +343,7 @@ public virtual async Task<PayPalResponse> RefundPaymentAsync(RefundPaymentReques
             }
 
             var refundRequest = new CapturesRefundRequest(request.Order.CaptureTransactionId)
-                .WithBody(message)
-                .WithRequestId(request.Order.Id.ToString());
+                .WithBody(message);
 
             var response = await ExecuteRequestAsync(refundRequest, request.Order.StoreId, cancelToken);