Set a default for upper_constraints_check.status
Set a default for upper_constraints_check.status

On occasion the Ansible URI module may not return
a status key, so this patch ensures that even if
it doesn't there will still be a value of '503'
which translates into a 'Service Unavailable'
error.

Change-Id: Ie944152f56bd5c68cfd80d406cf4175e9723c8f6
(cherry picked from commit 2fe22673612a983dbd9e00b9c74e5d737412987c)

yanyao/newton,yanyao/newton