safari无痕浏览模式下，setItem抛出异常导致程序不能正常运行

safari_private_mode_isssue.js

// cause safari private mode do not support storage

if (typeof localStorage === 'object') {
  try {
    localStorage.setItem('localStorage', 1);
    localStorage.removeItem('localStorage');
  } catch (e) {
    Storage.prototype._setItem = Storage.prototype.setItem; 
    Storage.prototype.setItem = function() {};
    alert('你的浏览器似乎不支持本地缓存，如果你是Safari用户，请关闭“无痕浏览”模式');
  }
}