do not overwrite files with local users/groups when restoring authconfig
the patch fixes regression in ipa-restore caused by overwriting /etc/passwd,
/etc/shadow and fiends during restore of authconfig configuration files. These
files are now excluded from authconfig backup dir.
https://fedorahosted.org/freeipa/ticket/5328
Reviewed-By: David Kupka <dkupka@redhat.com>