Swiftclient put bytes has no reset

[mathieu longtin]

In this line:
https://opendev.org/openstack/python-swiftclient/src/branch/master/swiftclient/client.py#L1999

Instead of:

   if isinstance(contents, str) or not contents:

It should be:

   if isinstance(contents, (six.text_type, six.binary_type)) or not contents:

The current implementation fails to retry on failure when submitting bytes instead of a string.