Comment 1 for bug 1766235

For additional info:

The headers provided by python-glanceclient (token is replaced by a dummy):
```
dict_items([('User-Agent', 'python-glanceclient'), ('X-Auth-Token', 'xxx'), (b'Content-Type', b'application/octet-stream')])
```

The received traceback:
```
Traceback (most recent call last):
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/python_glanceclient-2.9.0-py3.4.egg/glanceclient/common/utils.py", line 545, in inner
    return RequestIdProxy(wrapped(*args, **kwargs))
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/python_glanceclient-2.9.0-py3.4.egg/glanceclient/v2/tasks.py", line 102, in get
    resp, body = self.http_client.get(url)
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/keystoneauth1-3.5.0-py3.4.egg/keystoneauth1/adapter.py", line 304, in get
    return self.request(url, 'GET', **kwargs)
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/python_glanceclient-2.9.0-py3.4.egg/glanceclient/common/http.py", line 335, in request
    **kwargs)
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/keystoneauth1-3.5.0-py3.4.egg/keystoneauth1/adapter.py", line 189, in request
    return self.session.request(url, method, **kwargs)
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/keystoneauth1-3.5.0-py3.4.egg/keystoneauth1/session.py", line 732, in request
    logger=logger, split_loggers=split_loggers)
  File "/usr/libexec/vstorage-ui-backend/venv/lib64/python3.4/site-packages/keystoneauth1-3.5.0-py3.4.egg/keystoneauth1/session.py", line 393, in _http_log_request
    for header in sorted(headers.items()):
TypeError: unorderable types: bytes() < str()
```