fixes ZEN-13209: set controlplane_service_id to serviced if container.se...

...rviceID is null

ISSUE - this warning is output every minute:
```
WARN  [2014-07-31 21:55:16,549] org.zenoss.lib.tsdb.OpenTsdbClientFactory: Client returned error: put: illegal argument: invalid tag: controlplane_service_id=
...
WARN  [2014-07-31 21:56:26,549] org.zenoss.lib.tsdb.OpenTsdbClientFactory: Client returned error: put: illegal argument: invalid tag: controlplane_service_id=
...
```

DEMO - no longer any warnings:
```
# plu@plu-9: dockerid=$(docker ps --no-trunc | awk '/opentsdb/{print $1;exit}'); echo $dockerid
a27545aec5caf967bb6f580de550c7f05d69c40fb990331847b40751443e6b5b
~/src/europa
# plu@plu-9: pid=$(docker inspect --format '{{.State.Pid}}' $dockerid); echo $pid
9226
~/src/europa
# plu@plu-9: sudo nsenter -m -u -i -n -p -t $pid -- bash
root@a27545aec5ca:/# tail -f /opt/zenoss/log/metric-consumer-app.log
172.17.42.1 - - [31/Jul/2014:22:12:11 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 21 21
...
INFO  [2014-07-31 22:12:41,670] org.zenoss.app.consumer.metric.impl.OpenTsdbWriter: Shutting down writer due to dearth of work
172.17.42.1 - - [31/Jul/2014:22:12:41 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 24 24
INFO  [2014-07-31 22:12:41,689] org.zenoss.app.consumer.metric.impl.OpenTsdbWriterManager: Created 1 new writers
INFO  [2014-07-31 22:12:41,690] org.zenoss.app.consumer.metric.impl.OpenTsdbWriter: Starting writer
172.17.42.1 - - [31/Jul/2014:22:12:51 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 21 21
172.17.42.1 - - [31/Jul/2014:22:13:01 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 18 18
...
172.17.42.1 - - [31/Jul/2014:22:13:51 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 20 20
...
172.17.42.1 - - [31/Jul/2014:22:14:01 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 17 17
...
172.17.42.1 - - [31/Jul/2014:22:15:01 +0000] "POST /api/metrics/store HTTP/1.1" 200 48 17 17
...
```
I think the bug is on line 68.  The host registry is being created but the method used also adds the host stats to the container registry. The host registry metrics are reported separately starting on line 195