Disable Glance API v1

Disable Glance API v1

It has been deprecated since Newton [1].
Even if the related tests are skipped in latest tempest [2], API v1
has to be disabled in Gambia's tempest.conf [3].

[1] https://docs.openstack.org/glance/latest/user/glanceapi.html
[2] https://artifacts.opnfv.org/logs/functest/lf-pod1/2018-10-22_02-34-24/tempest_full/tempest-report.html
[3] https://artifacts.opnfv.org/logs/functest/lf-pod1/gambia/2018-10-23_10-34-07/tempest_full/tempest-report.html

Change-Id: I3b6bb632412c0fecaa659da262760af64d79fa71
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>