Thumbs gallery loop: TypeError: Cannot convert undefined or null to object

[MdWahiduzzamanEmon]

the documentation uses these props
```
thumbs={{
swiper: thumbsSwiper,
}}

which gives the error - **TypeError: Cannot convert undefined or null to object**


So the solution is - 
Use `thumbs={{ swiper: thumbsSwiper && !thumbsSwiper.destroyed ? thumbsSwiper : null }} these props instead.`

<Swiper
        cssMode={true}
        loop={true}
        spaceBetween={10}
        navigation={true}
        thumbs={{ swiper: thumbsSwiper && !thumbsSwiper.destroyed ? thumbsSwiper : null }}
/>