The internal kerberos_spnego provider was added as a replacement for
the omniauth-kerberos gem, the later is password-based and thus
vulnerable to the Zanarotti attack while the former is ticket-based. To
ease the transition before the removal of the password-based kerberos
provider, an override was added to make the kerberos_spnego provider
compatible with the kerberos provider existing identities, this
compatibility layer unfortunately introduced two bugs:
  https://gitlab.com/gitlab-org/gitlab/-/issues/241318
  https://gitlab.com/gitlab-org/gitlab/-/issues/344071

Since the removal of the old password-based kerberos provider in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/86036, we can now
rename the new provider, as suggested in
https://gitlab.com/gitlab-org/gitlab/-/issues/241318#note_409272802



Changelog: changed
EE: true

Signed-off-by: Marin Hannache <git@mareo.fr>