Added another 'cure' to root-element-cures

[nathanjansen]

I got the multiple root error when having a __construct() in a Trait class. While this seems a no brainer, do not use __construct() in a Trait, it happened to one of my developers. PHPStorm also does not show any errors or recommendations when using __construct() in a Trait class. To prevent more people from having the same issue, I added this pull request.