[css-ruby-1] Remove conflicting phrase about auto-hidden ruby's impact on layout. w3c#2649

Author: fantasai

css-ruby-1/Overview.bs

@@ -538,8 +538,7 @@ Autohiding Base-identical Annotations</h3>
 
 	If a [=ruby annotation=] has the exact same text content as its base,
 	it is <dfn lt="hidden ruby annotation | hidden annotation">hidden</dfn>.
-	Hiding a [=ruby annotation=] does not affect annotation [=pairing=]
-	or the block-axis positioning of boxes in other [=levels=].
+	Hiding a [=ruby annotation=] does not affect annotation [=pairing=].
 	However the [=hidden annotation=] is not visible,
 	and it has no impact on layout
 	other than to separate adjacent sequences of [=ruby annotation boxes=] within its level,