Description of problem:
After setting nsDS5ReplicaId to some value, we currently can't set it back.

Version-Release number of selected component (if applicable):
1.3.7.5-9.el7


How reproducible:
Always

Steps to reproduce:
  1. Enable replication
  2. Get current nsDS5ReplicaId value
  3. Set valid value to nsDS5ReplicaId
  4. Set nsDS5ReplicaId to the old value

Expected results:
nsDS5ReplicaId should be successfully changed.

Actual results:
ldap.OPERATIONS_ERROR: {'desc': 'Operations error', 'info': 'replica type is
already 2 - not changing'}