[2.0a1] After upgrade from 1.10, enabloing dhcp fails

After upgrade, I found this: https://bugs.launchpad.net/maas/+bug/1552444
After trying to enable dhcp:

"Subnet matching query does not exist."

2016-03-05 02:24:09 [-] Error on request (20) vlan.configure_dhcp: Subnet matching query does not exist.
        Traceback (most recent call last):
          File "/usr/lib/python3.5/threading.py", line 862, in run
            self._target(*self._args, **self._kwargs)
          File "/usr/lib/python3/dist-packages/provisioningserver/utils/twisted.py", line 794, in worker
            return target()
          File "/usr/lib/python3/dist-packages/twisted/_threads/_threadworker.py", line 46, in work
            task()
          File "/usr/lib/python3/dist-packages/twisted/_threads/_team.py", line 190, in doWork
            task()
        --- <exception caught here> ---
          File "/usr/lib/python3/dist-packages/twisted/python/threadpool.py", line 246, in inContext
            result = inContext.theWork()
          File "/usr/lib/python3/dist-packages/twisted/python/threadpool.py", line 262, in <lambda>
            inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
          File "/usr/lib/python3/dist-packages/twisted/python/context.py", line 118, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args, **kw)
          File "/usr/lib/python3/dist-packages/twisted/python/context.py", line 81, in callWithContext
            return func(*args,**kw)
          File "/usr/lib/python3/dist-packages/maasserver/utils/orm.py", line 448, in call_within_transaction
            return func_outside_txn(*args, **kwargs)
          File "/usr/lib/python3/dist-packages/maasserver/utils/orm.py", line 275, in retrier
            return func(*args, **kwargs)
          File "/usr/lib/python3.5/contextlib.py", line 30, in inner
            return func(*args, **kwds)
          File "/usr/lib/python3/dist-packages/maasserver/websockets/handlers/vlan.py", line 150, in configure_dhcp
            self._configure_iprange_and_gateway(parameters['extra'])
          File "/usr/lib/python3/dist-packages/maasserver/websockets/handlers/vlan.py", line 87, in _configure_iprange_and_gateway
            subnet = Subnet.objects.get(id=parameters['subnet'])
          File "/usr/lib/python3/dist-packages/django/db/models/manager.py", line 127, in manager_method
            return getattr(self.get_queryset(), name)(*args, **kwargs)
          File "/usr/lib/python3/dist-packages/django/db/models/query.py", line 334, in get
            self.model._meta.object_name
        maasserver.models.subnet.DoesNotExist: Subnet matching query does not exist.