upload to empty container broken under python 3

[Marco M]

In shell.py, when a warning is received from the server, a concatenation fails:

    if error.http_response_content:
        if msg:
            msg += ': '
        msg += error.http_response_content[:60]
    msg = ': %s' % msg

because http_response_content is of type bytes.

Python 2 - Warning: failed to create container 'foo': 409 Conflict: BucketAlreadyExists
Python 3 - TypeError: Can't convert 'bytes' object to str implicitly

[Cheng Li (shcli)]

it seems that this bug has been fixed by someone