优化购物车数量更新逻辑，当取不到qty字段时默认为1

src/custom/restcontroller/sale/shoppingcart/ShoppingCart.java

@@ -154,7 +154,7 @@ public class ShoppingCart extends Controller {
     @CACHEING_CLEAN(apiversions = {R.ID20220924095302.class})
     public String updateQty() throws YosException {
         Long sa_shoppingcartid = content.getLong("sa_shoppingcartid");
-        BigDecimal qty = content.getBigDecimalValue("qty");
+        BigDecimal qty = content.getBigDecimalValue("qty",1);
         BigDecimal length = content.getBigDecimalValue("length");
         BigDecimal width = content.getBigDecimalValue("width");
         ArrayList<String> sqlList = new ArrayList<>();