oslo.messaging holds connections when replies fail

Issue

• If client lost connectivity to RabbitMQ while RabbitMQ reports are fine, then system operator has to check if /var/log/nova/nova-conductor.log which contains line(s) similar to the following ones:

2016-09-01 16:29:00.312 43667 TRACE oslo_messaging.rpc.dispatcher NotFound: Exchange.declare: (404) NOT_FOUND - no exchange 'reply_8289518ccb6f479caf7638306f7034f0' in vhost '/'
...
2016-09-01 16:29:05.113 43649 TRACE oslo_messaging.rpc.dispatcher NotFound: Exchange.declare: (404) NOT_FOUND - no exchange 'reply_908b67a0fc53426382556dc247d71cad' in vhost '/'

• if found then system operator has to check /var/log/rabbitmq/rabbit@.log for the following lines:

=ERROR REPORT==== 1-Sep-2016::16:29:05 ===
connection <0.9523.0>, channel 1 - soft error:
{amqp_error,not_found,
            "no exchange 'reply_be26e71e75ad450e925360ccbebed0e3' in vhost '/'",
            'exchange.declare'}

=ERROR REPORT==== 1-Sep-2016::16:29:05 ===
connection <0.12407.0>, channel 2 - soft error:
{amqp_error,not_found,
            "no exchange 'reply_9d243e5fc03c4c229061f4ab43c52fbe' in vhost '/'",
            'exchange.declare'}

=ERROR REPORT==== 1-Sep-2016::16:29:05 ===
connection <0.1834.0>, channel 1 - soft error:
{amqp_error,not_found,
            "no exchange 'reply_6c42356adc0a4894914e2957afacde70' in vhost '/'",
            'exchange.declare'}