Fix s3proxy --version
Fix s3proxy --version

Regression from a65221091fbf103863cafa684cd6b72efff5e7d5.

kahing/s3proxy,timuralp/s3proxy,flandr/s3proxy,bouncestorage/s3proxy,flandr/s3proxy,kahing/s3proxy,andrewgaul/s3proxy,bouncestorage/s3proxy,andrewgaul/s3proxy,timuralp/s3proxy