SYSDB: return SYSDB_NAME from sysdb_initgroups
    
    For the GetGroupsList function it would be handy to get the user names as
    well with a single sysdb_initgroups() call. This patch adds SYSDB_NAME to
    the default attribute list.
    
    Reviewed-by: Pavel Březina <pbrezina@redhat.com>
    (cherry picked from commit cf2cc44d6293165379d6470b8bf6bb6a87d62b31)