rabbit_mnesia: add retries #30

Job	Run time
Build old RabbitMQ	2m 23s
Build new RabbitMQ	2m 9s
Test transient_queue + 3 node(s)	1m 3s
Test durable_queue + 3 node(s)	1m 27s
Test topic_bindings_import + 3 node(s)	6m 38s
Test 100k_queues_import + 3 node(s)	6m 27s
Test 100k_queues_import + 1 node(s)	3m 43s
Test durable_queue + 1 node(s)	51s
Test topic_bindings_import + 1 node(s)	2m 8s
	26m 49s

Provide feedback