[mediaqueries-5] prefers-reduced-data is a binary query

Closes #4833

Author: frivoal

mediaqueries-5/Overview.bs

@@ -2905,9 +2905,6 @@ Detecting the desire for reduced data usage when loading a page: the 'prefers-re
 	A Privacy and Security section should be added to this spec,
 	and it should address this concern.
 
-	Issue(4833): It might be useful for this feature to be more than a binary switch,
-	and instead express different degrees of preference for limited data.
-
 	Issue(4834): This feature is an early draft,
 	and the CSS-WG does not consider it ready for shipping in production.