Fix `LogTypeEnum` typedef
Fix `LogTypeEnum` typedef

See [this comment](https://github.com/microsoft/TypeScript/pull/33411#discussion_r324371317) - the type is incorrect for what's desired here.
EliteScientist/webpack,webpack/webpack,SimenB/webpack,webpack/webpack,SimenB/webpack,EliteScientist/webpack,webpack/webpack,SimenB/webpack,NekR/webpack,SimenB/webpack,NekR/webpack,webpack/webpack