AMQP vhost should not contain leading / from URL path

According to AMQP URI spec, vhost name does not include the leading / as normally present in URI path.
This, leading / has to be stripped from the path in order to be use as a vhost. For details see: http://www.rabbitmq.com/uri-spec.html

Signed-off-by: Maciej Borzecki <maciej.borzecki@open-rnd.pl>
Signed-off-by: Maciej Borzecki <maciek.borzecki@gmail.com>