SDAP: Remove user from cache for missing user in LDAP
Function sysdb_get_real_name overrode reurned code LDAP
and thus user was not removed from cache after removing it from LDAP.
This patch also do not try to set initgroups flag if user
does not exist. It reduce some error message.
Reviewed-by: Michal Židek <firstname.lastname@example.org>
(cherry picked from commit 9fc96a4a2b07b92585b02dba161ab1eb2dbdad98)