Failed to execute postMessage on DOMWindow

Hi !

The following error keeps showing up constantly for a few days.

- the website uses HTTPS
- there is no autoplay
- the origin is set manually just in case (ie: no `window.location.origin`)

```
www-widgetapi.js:629 Failed to execute 'postMessage' on 'DOMWindow': The target origin provided ('https://youtube.com') does not match the recipient window's origin ('https://www.DOMAIN.TLD').
```

Tested on Chrome, Firefox and Safari.

The code is as follow:

```js
this._player = new YTPlayer('#player', {
width: '100%',
height: '100%',
caption: false,
controls: false,
keyboard: false,
fullscreen: true,
annotations: false,
modestBranding: true,
related: false,
host: 'https://www.youtube.com',
showInfo: false,
origin: 'https://www.DOMAIN.TLD'
})
this._player.load(this._YTVideoID)
```

Did I miss something?