Bump express from 4.16.3 to 4.16.4

Bumps [express](https://github.com/expressjs/express) from 4.16.3 to 4.16.4.
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](https://github.com/expressjs/express/compare/4.16.3...4.16.4)
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