Fix Nodepool DIB Uploads to Glance w/o region_name
Fix Nodepool DIB Uploads to Glance w/o region_name

In a nodepool configuration that does not use the optional "region_name", avoid the
inevitable python KeyError: 'region_name' which is not defined for that case.

Story: 2000020

Change-Id: I64e32e88081082247407236850d2dd6b81666fef

seandst/nodepool,Tesora/tesora-nodepool,citrix-openstack/nodepool,seandst/nodepool,citrix-openstack/nodepool,Tesora/tesora-nodepool