GatewayChoiceType not initialized as service

[GGGGino]

Hi,

i see that the FormType "Payum\Core\Bridge\Symfony\Form\Type\GatewayChoiceType" is not initialized as service, so when i use it in a form it gives me an exception because the constructor expects an array, but null is passed.

Type error: Too few arguments to function Payum\Core\Bridge\Symfony\Form\Type\GatewayChoiceType::__construct(), 0 passed in /{root}/vendor/symfony/symfony/src/Symfony/Component/Form/FormRegistry.php on line 89 and exactly 1 expected

The form type "Payum\Core\Bridge\Symfony\Form\Type\GatewayFactoriesChoiceType" is correctly initialized with the "%payum.available_gateway_factories%" parameter instead.

<service id="payum.form.type.gateway_factories_choice" class="Payum\Core\Bridge\Symfony\Form\Type\GatewayFactoriesChoiceType">
    <argument>%payum.available_gateway_factories%</argument>
    <tag name="form.type" />
</service>