Some replication status data are reset upon a restart

[tbordaz]

Issue Description
The replication agreement contains operational attributes related to the total init

• nsds5replicaLastInitStart
• nsds5replicaLastInitEnd
• nsds5replicaLastInitStatus

Those attributes are reset after restarting DS. So the consumer may erroneously appear not yet initialized and
we are loosing the time when it was initialized.

Package Version and Platform:

• all versions

Steps to Reproduce
testcase provided

Expected results
The total init date (start/end) and the total init status should be preserved during restart

[tbordaz]

9e09235..e6ad63b main
0c8829b..cea43e0 389-ds-base-3.0
c171080..39282eb 389-ds-base-2.6
ce495ef..a303da8 389-ds-base-2.5
5f48c27..9c95995 389-ds-base-2.4
b1ec106..4a10a3f 389-ds-base-2.3
80da932..70eb45b 389-ds-base-2.2
c799628..db0c394 389-ds-base-2.1
82e65f4..3d897ed 389-ds-base-2.0