b2a862fdb3
Add logic to handle cases where a race between logical router port and load balancer creation renders the affected logical switch without the proper load balancer in its attribute. This change adds _get_subnet() to the helper module, so obtaining the subnet is done from a shared location. Closes-bug: #1931639 Change-Id: Ie4a843fc5dd98fc25f8cecf91997e275c36f121d