Plugin cleanup UCaptureMachine::Close() is not thread safe

[jimsimonz]

The texture target is deleted at a time when the docapture is running in another thread during close.

This causes crashes in the renderer as the texture gets killed during render. As it's multithreaded this is occasional.

Changing the close order to below is better as it kills the thread before destroying the texture. Also the texture needed nulling.

```

if (CaptureThread) { CaptureThread->Kill(true); CaptureThread->WaitForCompletion();

    delete CaptureThread;
    CaptureThread = nullptr;
}
if (TextureTarget)
{
    TextureTarget->ReleaseResource();
    TextureTarget = nullptr;
}

[jimsimonz]

Thanks for the plugin though it's great :)

[ayumax]

Thank you for the suggestion.

After applying the proposed correction, I will confirm the operation.

[ayumax]

Thank you for the report. I've fixed it in the lateset version: https://github.com/ayumax/WindowCapture2D/releases/tag/v1.0.1

[jimsimonz]

Great thanks.