Fixed a typo in error message
Fixed a typo in error message

The error message were not listing the nodes that are not found. This
was a typo I believe.

Change-Id: Ia3edb3f69cc39781aa86decbdc0efadd475bb2cf

stackforge/senlin,tengqm/senlin-container,stackforge/senlin,openstack/senlin,tengqm/senlin-container,openstack/senlin,openstack/senlin