[Simple Client] The simple client requires amqp-ext even if you use another brokers

[cbonnissent]

You need to install the amqp-ext broker (with the php extension for rabbit mq) if you want to use the client (even if you just want to use the fs broker).

The amq broker is auto registered in the buildContainerExtension https://github.com/php-enqueue/simple-client/blob/master/SimpleClient.php#L304

I have commented the registration and the SimpleClient seems to work well without