chore(deps): update http-proxy-middleware requirement (#4151)
chore(deps): update http-proxy-middleware requirement (#4151)

Updates the requirements on [http-proxy-middleware](https://github.com/chimurai/http-proxy-middleware) to permit the latest version.
- [Release notes](https://github.com/chimurai/http-proxy-middleware/releases)
- [Changelog](https://github.com/chimurai/http-proxy-middleware/blob/master/CHANGELOG.md)
- [Commits](https://github.com/chimurai/http-proxy-middleware/compare/v0.19.0...v0.20.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
driftyco/ionic-cli,driftyco/ionic-cli,driftyco/ionic-cli