Comment 5 for bug 1817782

In stein stable branch, UnicodeError is popping out in completion_cache when username has special characters like flügel. We need to cherry pick the fix to stein branch as well.

    self.vol_types = self.cclient.volume_types.list()
  File "/usr/lib/python2.7/site-packages/cinderclient/v3/volume_types.py", line 92, in list
    return self._list("/types%s" % (query_string), "volume_types")
  File "/usr/lib/python2.7/site-packages/cinderclient/base.py", line 98, in _list
    with self.completion_cache('human_id', obj_class, mode="w"):
  File "/usr/lib64/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/usr/lib/python2.7/site-packages/cinderclient/base.py", line 276, in completion_cache
    uniqifier = hashlib.md5(username.encode('utf-8') +
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 2: ordinal not in range(128)