The glance_api_servers points to a list of glance_api_servers for both
cinder and nova. This causes "nova image-list" to fail when glance api
servers are unavailable. Pointing to the LB VIP works as intended, so
removing this var in favour of the "host/port" vars ensures that only
the glance servers that are available are used.
glance_api_servers is still available and if specified will be used in
favour of host/port, but default it is commented out and the host/port
will be used - which uses the internal_lb_vip_address and default
glance_api_service_port.
Change-Id: I6794a1a266d22944be8d5634ee0c0ce6cd9f2c59
Closes-Bug: #1461245
82b431eba5