Correct name of CC BY-SA 4.0 license

Version 4.0 of the CC BY-SA license was written in a way that didn't
require to be ported to different legal jurisidictions, thus it is
correctly known as the "Creative Commons Attribution-ShareAlike 4.0
International License" not the "Creative Commons
Attribution-ShareAlike 4.0 Unported License".

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/policies/copyrights.md

@@ -11,7 +11,7 @@ aliases = [
 
 The text of the Apertis website is copyrighted (automatically, under the
 Berne Convention) by Apertis editors and contributors and is formally
-licensed under Creative Commons Attribution-ShareAlike 4.0 Unported
+licensed under Creative Commons Attribution-ShareAlike 4.0 International
 License (CC BY-SA) unless explicitly stated otherwise.
 
 The licenses that the Apertis website uses grant free access to our content