Merge branch 'release/4.8' of http://git.yoho.cn/fe/yohobuypc into release/4.8

@@ -491,6 +491,16 @@ class HelperSearch
                 'checked' => isset(self::$params['ageLevel']) && self::$params['ageLevel'] == $href ? true : false
             );
         }
+
+        //如果只有一个选项,默认选中
+        if (count($filter['ageLevel'],COUNT_NORMAL) === 1){
+            self::$selected['ageLevel'] = array(
+                'name' => $filter['ageLevel']['0']['name'],
+                'href' => self::buildUrl($params)
+            );
+
+            $result['0']['checked'] = true;
+        }
         return $result;
     }