In ::glance::api, os_region_name is set in DEFAULT which work for both
Juno & Kilo.
'glance_store' section has been introduced in Kilo which breaks Juno.
Until we decide our policy to manage master, let's use DEFAULT so both
releases work well.
Change-Id: I1c519146d3fe62f8c8fc8c2d85805db11af21e4c
b76fbcbea3