Bug: fbx animation export: to_ktime

[luuyiran]

hello，when I use assimp to export fbx animation, I found it can not dispaly correctly.
I find its k time array maybe wrong, I modified the code like this, my fbx animation finaly can dislay correctly.

this is my modification:

// FBXExporter.cpp line 1066
int64_t to_ktime(double ticks, const aiAnimation* anim) {
    if (anim->mTicksPerSecond <= 0) {
        return static_cast<int64_t>(ticks) * FBX::SECOND;
    }
    int64_t ret = static_cast<int64_t>((ticks / anim->mTicksPerSecond) * FBX::SECOND);
    return ret;
}

// line 2418/2432/2450
times.push_back(to_ktime(k.mTime, anim));

// line 2767, 1028 may means linear interpolate
n.AddChild("KeyAttrFlags", std::vector<int32_t>{1028});

now, my skeleton animation works fine, but morph animation still not work, I have writen the bs wights channel data into fbx, may be the connections not correct yet...