Python 3: do not use __builtin__
Python 3: do not use __builtin__

Use six.moves.builtins instead, this works with both Python 2 and 3.

Change-Id: I17cdf651edbf7907e2b8b3d6aec9ace8a76b0110
Closes-Bug: 1289107

alexpilotti/python-glanceclient,JioCloud/python-glanceclient,varunarya10/python-glanceclient,mmasaki/python-glanceclient,openstack/python-glanceclient,varunarya10/python-glanceclient,openstack/python-glanceclient,JioCloud/python-glanceclient,klmitch/python-glanceclient,klmitch/python-glanceclient,mmasaki/python-glanceclient,alexpilotti/python-glanceclient