更新产品扩展字段

@@ -108,7 +108,7 @@ class ProductLogic extends  BaseLogic
         }
         foreach ($extend as $k => $v){
             if(empty($v['values'])){
-                unset($extend[$k]);
+                continue;
             }
             unset($v['title']);
             if($v['type'] == 3 || $v['type'] == 4){