start.py: catch NoNodeError on delete
start.py: catch NoNodeError on delete

This was often producing an exception when the node did not exist.

Change-Id: Ida2238ea9dedea752d2c72facef2dde7469dd851

asalkeld/kolla-mesos,openstack/kolla-mesos,openstack/kolla-mesos,openstack/kolla-mesos