glance_multiple_locations when NovaEnableRbdBackend=true
glance_multiple_locations when NovaEnableRbdBackend=true

glance_multiple_locations does not needed when the
NovaEnableRbdBackend=false, but it is neede when both the
image and the instance storage is rbd and
the show_image_direct_url is enabled.

The condition introduced in Ia7e0558e4f318640981abb44d188e3479b5eae69

Change-Id: Ia8a8cd9aeda69e9a7db6f95dcf418f56e29cae00
Closes-Bug: 1632285
(cherry picked from commit 0ff21f83f34212127252773a77e843c6344152db)

trozet/opnfv-tht,trozet/opnfv-tht,trozet/opnfv-tht