Use CELERY_RESULT_PERSISTENT config to setup queue durability

Currently tornado-celery declares result queue with `durable=True` even if `CELERY_RESULT_PERSISTENT` is set to False and results in following error:

```
Received remote Channel.Close (406): PRECONDITION_FAILED - parameters for queue '8b2826c210924527a58f4c36a1467159' in vhost '/' not equivalent
```

This fix declare the queue durability using value of configured `CELERY_RESULT_PERSISTENT`.