This diff fixes the following bug:
When the rabbitMQ queue for the tunnelbroker-id is not created (clean rabbitMQ instance) there is an error when creating a new one:
AMQP: Queue creation error: PRECONDITION_FAILED - inequivalent arg 'x-expires' for queue 'tunnelbroker1' in vhost '/'.
We must remove conversion to the string when initializing the queue attribute. That fixes the error.