Reduce logging in BackupLogCleaner

Every minute log cleaner logs the following:

2016-11-21 11:23:09,565 DEBUG [ve0524.halxg.cloudera.com,16000,1479750005565_ChoreService_1] impl.BackupSystemTable: Has backup sessions from hbase:backup
2016-11-21 11:23:09,567 DEBUG [hconnection-0x4e9c4023-shared-pool11-t85] ipc.RpcConnection: Use SIMPLE authentication for service ClientService, sasl=false
2016-11-21 11:23:09,568 DEBUG [hconnection-0x4e9c4023-shared-pool11-t85] ipc.NettyRpcConnection: Connecting to ve0528.halxg.cloudera.com/10.17.240.22:16020
2016-11-21 11:23:09,575 DEBUG [hconnection-0x4e9c4023-shared-pool11-t86] ipc.RpcConnection: Use SIMPLE authentication for service ClientService, sasl=false
2016-11-21 11:23:09,576 DEBUG [hconnection-0x4e9c4023-shared-pool11-t86] ipc.NettyRpcConnection: Connecting to ve0528.halxg.cloudera.com/10.17.240.22:16020
2016-11-21 11:23:09,579 DEBUG [ve0524.halxg.cloudera.com,16000,1479750005565_ChoreService_1] ipc.RpcConnection: Use SIMPLE authentication for service ClientService, sasl=false
2016-11-21 11:23:09,579 DEBUG [ve0524.halxg.cloudera.com,16000,1479750005565_ChoreService_1] ipc.NettyRpcConnection: Connecting to ve0528.halxg.cloudera.com/10.17.240.22:16020
2016-11-21 11:23:09,581 DEBUG [ve0524.halxg.cloudera.com,16000,1479750005565_ChoreService_1] master.BackupLogCleaner: BackupLogCleaner has no backup sessions
2016-11-21 11:23:09,760 DEBUG [Default-IPC-NioEventLoopGroup-1-51] ipc.NettyRpcDuplexHandler: shutdown connection to ve0528.halxg.cloudera.com/10.17.240.22:16020 because idle for a long time
2016-11-21 11:23:09,775 DEBUG [Default-IPC-NioEventLoopGroup-1-52] ipc.NettyRpcDuplexHandler: shutdown connection to ve0528.halxg.cloudera.com/10.17.240.22:16020 because idle for a long time
2016-11-21 11:23:09,778 DEBUG [Default-IPC-NioEventLoopGroup-1-53] ipc.NettyRpcDuplexHandler: shutdown connection to ve0528.halxg.cloudera.com/10.17.240.22:16020 because idle for a long time