Bump http-proxy from 1.15.2 to 1.18.1

Bumps [http-proxy](https://github.com/http-party/node-http-proxy) from 1.15.2 to 1.18.1.
- [Release notes](https://github.com/http-party/node-http-proxy/releases)
- [Changelog](https://github.com/http-party/node-http-proxy/blob/master/CHANGELOG.md)
- [Commits](http-party/node-http-proxy@1.15.2...1.18.1)

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