尽管有活动，ExpressJS会话即将到期

如果其他人有相同的问题，这是解决方案：

function (req, res, next) {    if ('HEAD' == req.method || 'OPTIONS' == req.method) return next();    // break session hash / force express to spit out a new cookie once per second at most    req.session._garbage = Date();    req.session.touch();    next();}