Assign url type to source fail to load the animation

[SteveKChiu]

If I assign an url (not string) to the source property, the LottieAnimation fail to play, for example:

LottieAnimation {
    source: Qt.resolvedUrl("aaa/a.json")
}

It seems the source can accept javascript object as well, but url is also an 'object' type in qml, the code even have the comment:

if (typeof source === "object") { // TODO what about QUrl, I think it is treated as {} here

I would suggest test of actual lottie property in this case (like 'v' in lottie spec)

https://github.com/airbnb/lottie-web/blob/master/docs/json/animation.json

if ((typeof source === "object") && source["v"]) {

That should solve the problem.

[kbroulik]

Pull requests welcome :)