fix typo in doc
fix typo in doc

Change-Id: I5fb5d2e59c3e4e89cdfd156fd5ae65a5a8ab40ba
Signed-off-by: chohoor <bccdb0648df6eba51b3b110d8b382c29d05ca509@gmail.com>

stackforge/senlin,openstack/senlin,openstack/senlin,openstack/senlin,stackforge/senlin