Fix deprecation in RouteCollectionBuilder

[bobdenotter]

No description provided.

[I-Valchev]

Clean code, up-to-date code! 👍

[XWB]

@bobdenotter This change results in the following error:

Argument 1 passed to Bolt\Kernel::configureRoutes() must be an instance of Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator, instance of Symfony\Component\Routing\RouteCollectionBuilder given, called in vendor/symfony/framework-bundle/Kernel/MicroKernelTrait.php on line 93

Symfony 4.4.13

[bobdenotter]

@XWB Could you update to SF 5? I assume you're on an older 4.0 beta/RC that you've ran composer update on, right?

See here: https://github.com/bolt/project/blob/master/composer.json#L48-L54

[XWB]

@bobdenotter Thanks, you're right. Updating to Symfony 5.1 resolves my issue.