Simplify this code, using `??` operator

[birdofpreyru]

react-global-state/src/useAsyncData.ts

Lines 219 to 226 in a12c2cb

	const maxage: number = options.maxage === undefined
	? DEFAULT_MAXAGE : options.maxage;
	const refreshAge: number = options.refreshAge === undefined
	? maxage : options.refreshAge;
	const garbageCollectAge: number = options.garbageCollectAge === undefined
	? maxage : options.garbageCollectAge;