SDAP: allow GSS-SPNEGO for LDAP SASL bind as well
From the LDAP client perspective GSS-SPNEGO and GSSAPI are quite
similar. To support GSS-SPNEGO SSSD must make sure that a Kerberos
ticket is available before the LDAP SASL bind is started.
Related to https://pagure.io/SSSD/sssd/issue/4006
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>