Group counter stats request and group description stats request malformed

When connected to an OVS mininet, OVS rejects the Group Counter Statistics requests and the Group Description Statistics requests.

1. Start the controller

2. Start mininet: sudo mn --topo single,3 --controller 'remote,ip=192.168.4.1:6653' --switch ovsk,protocols=OpenFlow13

3. Observe wireshark or logs as shown below, for example:

Error notification flow Xid.........................34
-----------------------------------------------------------------------------------
2014-01-11 14:36:28.670 PST [pool-22-thread-4] INFO o.o.c.sal.binding.impl.NotifyTask - Notification delivered NodeErrorNotification [_code=1, _data=^D^R^@^X@^@@"^@^F@^@@^@@^@����, _type=BadRequest, _transactionId=TransactionId [_value=34], _transactionUri=null, augmentation=[]] to org.opendaylight.controller.sal.compatibility.FlowProgrammerAdapter$$Broker$ListenerInvoker@1b8bc4da
2014-01-11 14:36:28.670 PST [pool-22-thread-5] INFO o.o.c.sal.binding.impl.NotifyTask - Notification delivered NodeErrorNotification [_code=1, _data=^D^R^@^X@^@@"^@^F@^@@^@@^@����, _type=BadRequest, _transactionId=TransactionId [_value=34], _transactionUri=null, augmentation=[]] to org.opendaylight.openflowplugin.test.OpenflowpluginTestCommandProvider$FlowEventListener$$Broker$ListenerInvoker@53b72d18
2014-01-11 14:36:28.670 PST [pool-22-thread-3] INFO o.o.c.sal.binding.impl.NotifyTask - Delivering notification MeterStatisticsUpdated [_moreReplies=false, _id=Uri [_value=openflow:1], _nodeConnector=null, _transactionId=TransactionId [_value=35], _meterStats=[], augmentation=[]] to org.opendaylight.controller.md.statistics.manager.StatisticsUpdateCommiter$$Broker$ListenerInvoker@3cfde83a
2014-01-11 14:36:28.670 PST [pool-22-thread-3] INFO o.o.c.sal.binding.impl.NotifyTask - Notification delivered MeterStatisticsUpdated [_moreReplies=false, _id=Uri [_value=openflow:1], _nodeConnector=null, _transactionId=TransactionId [_value=35], _meterStats=[], augmentation=[]] to org.opendaylight.controller.md.statistics.manager.StatisticsUpdateCommiter$$Broker$ListenerInvoker@3cfde83a
2014-01-11 14:36:28.670 PST [pool-22-thread-1] INFO o.o.c.sal.binding.impl.NotifyTask - Delivering notification NodeErrorNotification [_code=1, _data=^D^R^@^P
^@@^@$@^G@^@@^@@^@, _type=BadRequest, _transactionId=TransactionId [_value=36], _transactionUri=null, augmentation=[]] to org.opendaylight.controller.sal.compatibility.FlowProgrammerAdapter$$Broker$ListenerInvoker@1b8bc4da
2014-01-11 14:36:28.670 PST [pool-22-thread-2] INFO o.o.c.sal.binding.impl.NotifyTask - Delivering notification NodeErrorNotification [_code=1, _data=^D^R^@^P
^@@^@$@^G@^@@^@@^@, _type=BadRequest, _transactionId=TransactionId [_value=36], _transactionUri=null, augmentation=[]] to org.opendaylight.openflowplugin.test.OpenflowpluginTestCommandProvider$FlowEventListener$$Broker$ListenerInvoker@53b72d18
Error notification flow Xid.........................36
-----------------------------------------------------------------------------------
2014-01-11 14:36:28.670 PST [pool-22-thread-1] INFO o.o.c.sal.binding.impl.NotifyTask - Notification delivered NodeErrorNotification [_code=1, _data=^D^R^@^P@^@@$^@^G@^@@^@@^@, _type=BadRequest, _transactionId=TransactionId [_value=36], _transactionUri=null, augmentation=[]] to org.opendaylight.controller.sal.compatibility.FlowProgrammerAdapter$$Broker$ListenerInvoker@1b8bc4da
2014-01-11 14:36:28.670 PST [pool-22-thread-2] INFO o.o.c.sal.binding.impl.NotifyTask - Notification delivered NodeErrorNotification [_code=1, _data=^D^R^@^P@^@@$^@^G@^@@^@@^@, _type=BadRequest, _transactionId=TransactionId [_value=36], _transactionUri=null, augmentation=[]] to org.opendaylight.openflowplugin.test.OpenflowpluginTestCommandProvider$FlowEventListener$$Broker$ListenerInvoker@53b72d18