Make openstack_release more obvious

This is forwardport of [1].

[1] https://review.opendev.org/730496

Change-Id: I6523b915e0231c28b5cd91f821515f3d47309d66

ansible/group_vars/all.yml

@@ -50,7 +50,7 @@ kolla_dev_repos_directory: "/opt/stack/"
 kolla_dev_repos_git: "https://opendev.org/openstack"
 kolla_dev_repos_pull: "no"
 kolla_dev_mode: "no"
-kolla_source_version: "master"
+kolla_source_version: "{{ openstack_release }}"
 
 # Proxy settings for containers such as magnum that need internet access
 container_http_proxy: ""

etc/kolla/globals.yml

@@ -17,8 +17,8 @@
 # Valid options are [ binary, source ]
 #kolla_install_type: "binary"
 
-# Valid option is Docker repository tag
-#openstack_release: ""
+# Do not override this unless you know what you are doing.
+#openstack_release: "master"
 
 # Docker image tag used by default.
 #openstack_tag: "{{ openstack_release ~ openstack_tag_suffix }}"