Pod refresh errors when node has a logical volume

When refreshing a pod that contains a node with remote storage target being used as a logical volume group with a logical volume in that group, an error is thrown:

==> /var/log/maas/regiond.log <==
2017-04-18 15:42:00 maasserver.websockets.protocol: [critical] Error on request (50) pod.refresh: ['Cannot delete block device because its part of a volume group.']

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/twisted/internet/base.py", line 1203, in mainLoop
    self.runUntilCurrent()
  File "/usr/lib/python3/dist-packages/twisted/internet/base.py", line 798, in runUntilCurrent
    f(*a, **kw)
  File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 434, in errback
    self._startRunCallbacks(fail)
  File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 501, in _startRunCallbacks
    self._runCallbacks()
--- <exception caught here> ---
  File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 588, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/usr/lib/python3/dist-packages/maasserver/forms/pods.py", line 246, in wrap_errors
    raise PodProblem(str(failure.value))
maasserver.exceptions.PodProblem: ['Cannot delete block device because its part of a volume group.']