Update (git|review).openstack.org links to opendev

This updates links going to git.openstack.org and review.openstack.org
to go to their respective opendev locations to avoid redirects.

Change-Id: I78e3bb5303718962f591117f9c0ee11f2314b128
Closes-Bug: #1833256
diff --git a/doc/source/guides/multinode-lab.rst b/doc/source/guides/multinode-lab.rst
index 3c4acc8..15f02a0 100644
--- a/doc/source/guides/multinode-lab.rst
+++ b/doc/source/guides/multinode-lab.rst
@@ -103,7 +103,7 @@
 
 ::
 
-    git clone https://git.openstack.org/openstack-dev/devstack
+    git clone https://opendev.org/openstack/devstack
     cd devstack
 
 Up to this point all of the steps apply to each node in the cluster.