trace doesn't work with persistent exchanges

[Robert Collins]

Traceback (most recent call last):
  File "bin/oops-amqp-trace", line 26, in <module>
    oops_amqp.trace.main()
  File "/home/robertc/source/launchpad/oops-amqp/working/oops_amqp/trace.py", line 65, in main
    auto_delete=True)
  File "/home/robertc/source/launchpad/lp-sourcedeps/eggs/amqplib-0.6.1-py2.6.egg/amqplib/client_0_8/channel.py", line 843, in exchange_declare
    (40, 11), # Channel.exchange_declare_ok
  File "/home/robertc/source/launchpad/lp-sourcedeps/eggs/amqplib-0.6.1-py2.6.egg/amqplib/client_0_8/abstract_channel.py", line 105, in wait
    return amqp_method(self, args)
  File "/home/robertc/source/launchpad/lp-sourcedeps/eggs/amqplib-0.6.1-py2.6.egg/amqplib/client_0_8/channel.py", line 273, in _close
    (class_id, method_id))
amqplib.client_0_8.exceptions.AMQPChannelException: (406, u"PRECONDITION_FAILED - cannot redeclare exchange 'oopses' in vhost '/' with different type, durable, internal or autodelete value", (40, 10), 'Channel.exchange_declare')

I had to change both persistent and autodelete to the opposite values to let it work; may want them as CLI options.