Description of problem:
When removing collection of data center statistics did not remove all references.
There was a reference in the DeleteTimeKeepingJob

Version-Release number of selected component (if applicable):
4.0

How reproducible:
100%

Steps to Reproduce:
1.Install Engine DWH and 
2. Let the Delete process run at 3AM
3.

Actual results:
Exception in component tJDBCInput_2                                 
org.postgresql.util.PSQLException: ERROR: relation "datacenter_samples_history" does not exist                                 
  Position: 31                                 
        at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2198)                                 
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1927)                                 
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)                                 
        at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:565)                                 
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:406)                                 
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:286)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob.tJDBCInput_2Process(DeleteTimeKeepingJob.java:4098)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob.tJDBCCommit_1Process(DeleteTimeKeepingJob.java:3852)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob.tRunJob_2Process(DeleteTimeKeepingJob.java:3631)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob.tJDBCInput_1Process(DeleteTimeKeepingJob.java:3368)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob.tJDBCConnection_1Process(DeleteTimeKeepingJob.java:2757)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob.tJDBCConnection_2Process(DeleteTimeKeepingJob.java:2632)                                 
        at ovirt_engine_dwh.deletetimekeepingjob_4_0.DeleteTimeKeepingJob$2.run(DeleteTimeKeepingJob.java:12146)                                 
2016-05-25 03:00:00|QV2txu|uRHfVX|OQkyQe|OVIRT_ENGINE_DWH|DeleteTimeKeepingJob|Default|6|Java Exception|tJDBCInput_2|org.postgresql.util.PSQLException:ERROR: relation "datacenter_samples_history" does not exist   

Expected results:
Delete job should run with no errors

Additional info: