Trivial: Update pypi url to new url
Trivial: Update pypi url to new url

Pypi url changed from [1] to [2]

[1] https://pypi.python.org/pypi/<package>
[2] https://pypi.org/project/<package>

Change-Id: I93e71fa3bc447ff238633f938dc7cf93e9e22f05

openstack/oslo.privsep