Fixed XFRM\Service\ResourceItem\Icon::setImageFromExisting does not fail as expected if the icon is missing

public function setImageFromExisting(): bool
{
    $path = $this->resource->getAbstractedIconPath();
    if (!$this->app->fs()->has($path))
    {
        new \InvalidArgumentException(
            "Resource does not have an icon ({$path})"
        );
    }