Deprecate the identity-feature-enabled.reseller config option.

All supported version of OpenStack now supports the 'reseller'
[1] feature. So let's deprecate the related feature flag.

[1]: http://specs.openstack.org/openstack/keystone-specs/specs/kilo/reseller.html

Change-Id: Ia86c6f351919bddf2611524bf0b143aa09dbddee
2 files changed