Bump @types/webpack from 4.4.17 to 4.4.20
Bump @types/webpack from 4.4.17 to 4.4.20

Bumps [@types/webpack](https://github.com/DefinitelyTyped/DefinitelyTyped) from 4.4.17 to 4.4.20.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
styfle/react-server-example-tsx,styfle/react-server-example-tsx