message: refactor(throttleTime): small clean up
diff: @@ -84,8 +84,8 @@ import { timer } from '../observable/timer';
  export function throttleTime<T>(
  duration: number,
  scheduler: SchedulerLike = asyncScheduler,
  - { leading = false, trailing = false }: ThrottleConfig = defaultThrottleConfig
  + config = defaultThrottleConfig
  ): MonoTypeOperatorFunction<T> {
  - const d = timer(duration, scheduler);
  - return throttle(() => d, { leading, trailing });
  + const duration$ = timer(duration, scheduler);
  + return throttle(() => duration$, config);
  }
  