Please try to 'repro' and determine if this is something that should be addressed by changing the Python client.
This was caused by the remote_storage_wrappers module importing botocore before a check for whether boto3 was already installed. I've moved the import to after the import.
To validate, use pip to uninstall boto3 and botocore and try to import synapseclient. The chaining of imports should reach the remote_storage_wrappers module.
No more error.