AMQP connection doesn't close properly in health-probe.py

In rabbitmq logs, we found a lots of warning logs like this:
2020-07-01 03:20:49.905 [warning] <0.15755.8> closing AMQP connection <0.15755.8> (100.101.245.0:42826 -> 100.101.63.15:5672 - health-probe.py:3358809:973d246c-561e-4e1f-8ff9-39366c2e3c46, vhost: 'nova', user: 'nova'):
client unexpectedly closed TCP connection
2020-07-01 03:20:49.905 [warning] <0.15718.8> closing AMQP connection <0.15718.8> (100.101.245.0:42820 -> 100.101.63.15:5672 - health-probe.py:3358809:4f69aed8-dc94-4804-9b83-f9cc406b8e48, vhost: 'nova', user: 'nova'):
client unexpectedly closed TCP connection

It seems that health-probe.py doesn't close the amqp connections in a proper way. Even though it's not a serious problem, we can make a bit improvement in this script.