GET http://<host>:<port>/ with out an "Accept: " header causes glance-api to return a 500 error

Steps to reproduce issue:

Pull down lp:~jshepher/glance/functional_tests_using_httplib2_part2

test_003_version_variations, step #0 will cause a 500 from glance-api.

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Here is the stack trace from the error:

 DEBUG [eventlet.wsgi.server] Traceback (most recent call last):
  File "/Users/justinshepherd/Projects/bzr/glance/glance-trunk/.glance-venv/lib/python2.6/site-packages/eventlet/wsgi.py", line 336, in handle_one_response
    result = self.application(self.environ, start_response)
  File "/Users/justinshepherd/Projects/bzr/glance/glance-trunk/.glance-venv/lib/python2.6/site-packages/webob/dec.py", line 147, in __call__
    resp = self.call_func(req, *args, **self.kwargs)
  File "/Users/justinshepherd/Projects/bzr/glance/glance-trunk/.glance-venv/lib/python2.6/site-packages/webob/dec.py", line 208, in call_func
    return self.func(req, *args, **kwargs)
  File "/Users/justinshepherd/Projects/bzr/glance/functional_tests_using_httplib2/glance/common/wsgi.py", line 110, in __call__
    response = self.process_request(req)
  File "/Users/justinshepherd/Projects/bzr/glance/functional_tests_using_httplib2/glance/api/middleware/version_negotiation.py", line 77, in process_request
    accept = req.headers['Accept']
  File "/Users/justinshepherd/Projects/bzr/glance/glance-trunk/.glance-venv/lib/python2.6/site-packages/webob/headers.py", line 135, in __getitem__
    return self.environ[_trans_name(hname)]
KeyError: 'HTTP_ACCEPT'