dsdb: Further assert that we always have an objectClass and an rDN

We must have these two elements in a replPropertyMetaData for it to be
valid.

We may have to relax this for new partition creation, but for now we
want to find and isolate the database corruption.

The printing of the LDIF is moved above the checks to make it easier
to diagnoise the failures when further reproduced.

Based initially on a patch originally by Arvid Requate <requate@univention.de>

Andrew Bartlett

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Change-Id: I5f583d89e6d4c5e8e2d9667f336a0e8fd8347b25
Reviewed-on: https://gerrit.samba.org/164
Reviewed-by: Kamen Mazdrashki <kamenim@samba.org>

Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Mon Mar 17 06:44:17 CET 2014 on sn-devel-104