fix 商品列表筛选条件品牌没有数据时bug

@@ -331,6 +331,10 @@ class FilterTools {
     handleFilterBrand() { // 组装brand筛选数据
         let {baseUrl, origin, params} = this;
         const filter = _.get(origin, 'filter', {});
+
+        if (!filter.brand.length) {
+            return false;
+        }
         const brands = [];
         const href = handleFilterUrl(baseUrl, params, {brand: '${brand}'});
         const brandids = _.split(params.brand, ',');