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/README.rst b/README.rst
index ad7ede4..f3a585a 100644
--- a/README.rst
+++ b/README.rst
@@ -38,7 +38,7 @@
 `stackrc` for the default set).  Usually just before a release there will be
 milestone-proposed branches that need to be tested::
 
-    GLANCE_REPO=https://git.openstack.org/openstack/glance.git
+    GLANCE_REPO=https://opendev.org/openstack/glance.git
     GLANCE_BRANCH=milestone-proposed
 
 Start A Dev Cloud