Move to opendev

Use review.opendev.org instead of review.openstack.org.

You can see the discussion below:
http://lists.openstack.org/pipermail/openstack-discuss/2019-March/003603.html

Change-Id: Ib73394bac68327b1afbd246aa1a3470bac8adc92

manifests/releasenotes/notes/split_vendordata_from_metadata-5bc86b342574d8e8.yaml

@@ -2,7 +2,7 @@
 fixes:
   - |
     A recent change making nova-metadata-api work with wsgi
-    https://review.openstack.org/#/c/582621/ moved the vendordata plugin
+    https://review.opendev.org/#/c/582621/ moved the vendordata plugin
     parameters to the nova::metadata manifest.
     While this is conceptually correct as nova-metadata is the one that
     should be using this parameters. In practice the parameters are also

releasenotes/notes/add_live_migration_with_native_tls-4293ca305e98cdc3.yaml

@@ -1,5 +1,5 @@
 ---
 features:
   - |
-    https://review.openstack.org/625216 introduces a new setting which needs
+    https://review.opendev.org/625216 introduces a new setting which needs
     set to true if native TLS for migration and disks over NBD is being used.

releasenotes/notes/deprecate_notify_on_api_faults-c7eb47adc3c92671.yaml

@@ -3,4 +3,4 @@ deprecations:
   - |
     The ``notify_on_api_faults`` parameter is deprecated as
     it is also removed from nova config options in change
-    ``https://review.openstack.org/#/c/505164``.
+    ``https://review.opendev.org/#/c/505164``.

releasenotes/notes/update_cinder_catalog_info_v2_to_v3-c5d442dbbae2327e.yaml

@@ -4,4 +4,4 @@ upgrade:
     ::os_service_default(use default set by nova which is currently
     'volumev3:cinderv3:publicURL') from 'volumev2:cinderv2:publicURL'
     because nova has removed the support of cinderv2 in
-    https://review.openstack.org/#/c/501874/.
+    https://review.opendev.org/#/c/501874/.