Update typings to latest DefinitelyTyped revision

Update the typings in the cordova-plugin-inappbrowser to match the current revision published via DefinitelyTyped.
This fixes e.g. this issue: https://stackoverflow.com/q/42095516/1902598
DefinitelyTyped PR: https://github.com/DefinitelyTyped/DefinitelyTyped/pull/17192