Catch the case when no new messages are available
Catch the case when no new messages are available

Confluent Kafka client throws the KafkaError._PARTITION_EOF exception
when no new messages are available in a given partitiion. We should
catch this case and continue consuming after a short sleep.

Story: 2003705
Task: 30116
Change-Id: I44add24df764bbc4e718358a8af75903e035f3f0

openstack/monasca-common,openstack/monasca-common,stackforge/monasca-common,openstack/monasca-common,stackforge/monasca-common,stackforge/monasca-common