[css-values-5] Fix acknowledgments link (#8375)

Author: bramus

css-values-5/Overview.bs

@@ -964,7 +964,7 @@ Generating/Caching Random Values: the <<random-caching-options>> value</h4>
 Acknowledgments</h2>
 
 	Firstly, the editors would like to thank
-	all of the contributors to the <a href="http://www.w3.org/TR/css-values-4/#acknowledgements">previous level</a>
+	all of the contributors to the <a href="https://www.w3.org/TR/css-values-4/#acknowledgments">previous level</a>
 	of this module.
 
 	Secondly, we would like to acknowledge