fix：修复总销售额不显示问题

src/main/java/com/gxwebsoft/shop/service/impl/DashboardServiceImpl.java

@@ -93,7 +93,7 @@ public class DashboardServiceImpl extends ServiceImpl<DashboardMapper, Dashboard
         List<OrderPay> totalOrderPayList = orderPayService.list(Wrappers.lambdaQuery(OrderPay.class)
                 .eq(OrderPay::getDeleted, 0)
                 .eq(OrderPay::getPayStatus, 20));//过滤付款的 TODO 这里不考虑巨量数据
-        if (null != totalOrderPayList && !orderPayList.isEmpty()) {
+        if (null != totalOrderPayList && !totalOrderPayList.isEmpty()) {
             totalSale = totalOrderPayList.stream().map(OrderPay::getOrderPrice).reduce(BigDecimal.ZERO, BigDecimal::add);
         }