Updated openstack/openstack
Project: openstack-dev/devstack  473b628eb9a9c733e47f9905e543018a075148f6
null
Fix typos in HACKING.rst

Two trivial fixes. One makes a broken external link work, the other
completes consistent casing (Devstack -> DevStack).

Change-Id: I147a3c5fe72071e9ebf24e7f226ba01a0a1204e3