Error: Call to a member function isOwner() on null when trying to read deleted group's review queue

Sentry Issue: ENGINE-4Y

Error: Call to a member function isOwner() on null
  File "/Controllers/api/v1/groups/review.php", line 22, in Minds\Controllers\api\v1\groups\review::get
    if (!$group->isOwner($user) && !$group->isModerator($user)) {
  File "/Api/Factory.php", line 70, in Minds\Api\Factory::build
    return $handler->$method($pages);
  File "/Controllers/api/api.php", line 76, in Minds\Controllers\api\api::get
    return Factory::build($pages, $this->request, $this->response);
  File "/Core/Router.php", line 138, in Minds\Core\Router::route
    return $handler->$method($pages);
  File "/index.php", line 9
    $router->route();