Fix usages of Symfony\Component\Form\Extension\Core\ChoiceList\SimpleChoiceList

[aivus]

Symfony\Component\Form\Extension\Core\ChoiceList\SimpleChoiceList deprecated since 2.7. Removed in 3.0

SHFormBundle/Form/Core/ChoiceList/AjaxSimpleChoiceList.php

Line 14 in e1fae05

use Symfony\Component\Form\Extension\Core\ChoiceList\SimpleChoiceList;