Why adding a host to RHV-M is failing with error "duplicate key value violates unique constraint "name_server_pkey""

Issue

• Adding a host to RHV-M is failing with the error below.

2018-08-15 08:19:16,251-05 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.CollectVdsNetworkDataAfterInstallationVDSCommand] (EE-ManagedThreadFactory-engine-Thread-1) [36b1820b] Failed in 'CollectVdsNetworkDataAfterInstallationVDS' method, for vds: 'host.example.com'; host: 'host.example.com': CallableStatementCallback; SQL [{call insertnameserver(?, ?, ?)}]; ERROR: duplicate key value violates unique constraint "name_server_pkey"
  Detail: Key (dns_resolver_configuration_id, address)=(d6b43bcd-f065-43f5-a5d8-7192b23dd761, 192.168.0.40) already exists.
  Where: SQL statement "INSERT INTO
    name_server(
      address,
      position,
      dns_resolver_configuration_id)
    VALUES (
      v_address,
      v_position,
      v_dns_resolver_configuration_id)"
PL/pgSQL function insertnameserver(uuid,character varying,smallint) line 3 at SQL statement; nested exception is org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "name_server_pkey"