flow capable stats are not in operational store

This bug is to track failures in CI.

https://jenkins.opendaylight.org/releng/view/openflowplugin/job/openflowplugin-csit-1node-cds-flow-services-all-master/

some test cases are looking for the presence of the string "flow-capable-node-connector-statistics" for a specific
node. It does not exist.

the log has one message that might be related:

2015-05-18 14:33:54,359 | WARN | CommitFutures-2 | StatisticsManagerImpl | 173 - org.opendaylight.openflowplugin.applications.statistics-manager - 0.1.0.SNAPSHOT | Failed to export Flow Capable Statistics, Transaction DOM-CHAIN-2-31 failed.
TransactionCommitFailedException

{message=canCommit encountered an unexpected failure, errorList=[RpcError [message=canCommit encountered an unexpected failure, severity=ERROR, errorType=APPLICATION, tag=operation-failed, applicationTag=null, info=null, cause=org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException: Node was deleted by other transaction.]]}

This started happening for the test job #429 which was triggered by this gerrit patch:
https://git.opendaylight.org/gerrit/#/c/20173/

Even though that was the OFP change that triggered the test job, it's possible that other projects
had made changes in between that made it in to the distribution that first saw the failures.