python-oops-datedir2amqp requires a null --key value

[Steve McInerney]

launchpad@asuka:/srv/oops-datedir2amqp/python-oops-datedir2amqp$ bin/datedir2amqp --exchange oopses --host asuka --username oops-datedir2amqp --password <blah> --vhost staging.launchpad.net --repo /srv/staging.launchpad.net/var/local-oopses-launchpad
Traceback (most recent call last):
  File "bin/datedir2amqp", line 26, in <module>
    oops_datedir2amqp.main()
  File "/srv/oops-datedir2amqp/python-oops-datedir2amqp-rev-3/oops_datedir2amqp/main.py", line 82, in main
    repo.republish(publisher)
  File "/srv/oops-datedir2amqp/python-oops-datedir2amqp-rev-3/eggs/oops_datedir_repo-0.0.10-py2.6.egg/oops_datedir_repo/repository.py", line 171, in republish
    oopsid = publisher(report)
  File "/srv/oops-datedir2amqp/python-oops-datedir2amqp-rev-3/eggs/oops_amqp-0.0.4-py2.6.egg/oops_amqp/publisher.py", line 95, in __call__
    message, self.exchange_name, routing_key=self.routing_key)
  File "/srv/oops-datedir2amqp/python-oops-datedir2amqp-rev-3/eggs/amqplib-0.6.1-py2.6.egg/amqplib/client_0_8/channel.py", line 2219, in basic_publish
    args.write_shortstr(routing_key)
  File "/srv/oops-datedir2amqp/python-oops-datedir2amqp-rev-3/eggs/amqplib-0.6.1-py2.6.egg/amqplib/client_0_8/serialization.py", line 337, in write_shortstr
    if len(s) > 255:
TypeError: object of type 'NoneType' has no len()

add --key "", and all works.