PAM: Use the override_space option
https://fedorahosted.org/sssd/ticket/2397
When using the override_default_space option, this patch allows to log
in using both the original name (space user) as well as the normalized
name (space_user).
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>