Infinite reschedule of flush

We observed in openflowplugin cbench test (before logging was set to ERROR)
https://jenkins.opendaylight.org/releng/job/openflowplugin-csit-1node-cbench-performance-only-boron many logs from OutboundQueueProviderImpl like "Replacing queue null with null". This is caused by infinite loop of flushing and closing AbstractOutboundQueueManager in ofjava - sometimes (on disconnect) there can be still some unflushed segments but thery are not able to be flushed if channel is not writable anymore. In local testing we got stuck with cpu on 97%