This is needed to fix the CI broken by glance switching to running
under wsgi, and thus breaking our assumption that glance is accessible
by host:port only.
The options glance_host, glance_port and glance_protocol were
deprecated. Standalone deployments should use glance_api_servers
instead.
Also removes two unused utility functions.
Change-Id: I54dc04ab084aeb7208c9dd9940c6434c029bf41c
Partial-Bug: #1699542