[AMQP 1.0] durable node property not signalled if specified on its own

When requesting creation of the node on demand when attaching, if the only thing specified for the node in the address string is that it is durable, that fact will not be communicated via the node-properties sent with the attach.

E.g. 'q; {,create:always,node:{durable:True}}' will not result in a durable queue being created (however if some other property is specified in addition, or if the durable property is specified through a nested properties map, then it will be).