Do not fail if there are multiple nsDS5ReplicaId values in cn=replication,cn=etc
On systems installed before #3394 was fixed and nsDS5ReplicaId became
single-valued, there are two replica ID values stored in cn=replication:
the default (3) and the actual value we want.
Instead of failing when multiple values are found, use the largest one.
Reviewed-By: Martin Kosek <email@example.com>