Fix of verify_glance_api_versions

verify_glance_api_versions was used .get_versions() method which is
work correctly only for RestClient and not applicable to child with
defined property api_version. Now it's switched to _get_api_versions
method.

Change-Id: Ie5e7b384d3a661f22b3f1d16ffca2beeb41de954
Partial-Bug: 1611771
2 files changed