Specify server id clearly on the gate test
Specify server id clearly on the gate test

When there are 2 nova nodes, devstack/exercise.sh loops forever.
This patch fixes this bug.

Change-Id: I0442e5b06c23ddf4771a9a404fc770965db503e4
Closes-Bug: #1472154

openstack/ironic-inspector,openstack/ironic-inspector