Setting fallback prop to a react element causes"Maximum call stack size exceeded" error

[QuinnStraus]

Setting the fallback prop on the ReactPlayer element to a react element leads to a "Maximum call stack size exceeded" RangeError. This seems to be caused by the call to deepmerge on line 37 of ReactPlayer.tsx failing to copy and merge the component.

[QuinnStraus]

This seems to be the same underlying issue as #1958 and can be fixed in the same way as #1933