Use the canonical URL for repositories (git.openstack.org)

- When the URL refers to cloning or using git repositories, use the
  cloning URL (https://git.openstack.org/<namespace>/<project>)
- When the URL refers to the browsable version of the repository, point to
  the cgit frontend (https://git.openstack.org/cgit/<namespace>/<project>)

Change-Id: Iaeaa153a05aa85b9cf7451ae3c28aec56722222c
diff --git a/devstack/README.rst b/devstack/README.rst
index 053afd4..490f833 100644
--- a/devstack/README.rst
+++ b/devstack/README.rst
@@ -22,4 +22,4 @@
 
 3. Run ``stack.sh`` found in the DevStack repo.
 
-.. _README file: https://github.com/openstack-dev/devstack/blob/master/README.rst
+.. _README file: https://git.openstack.org/cgit/openstack-dev/devstack/plain/README.rst