[css-display] Fix typo

Author: bangseongbeom

css-display-3/Overview.bs

@@ -1418,7 +1418,7 @@ Changes Prior to Candidate Recommendation Status</h3>
 		<li>
 			Distinguished “new” <a>formatting context</a> from <a>independent formatting context</a> since certain formatting contexts layer.
 			(<a href="https://github.com/w3c/csswg-drafts/issues/2597">Issue 2597</a>,
-			<a href="https://github.com/w3c/csswg-drafts/issues/1457">Issue 15457</a>)
+			<a href="https://github.com/w3c/csswg-drafts/issues/1457">Issue 1457</a>)
 		<li>
 			Defined that <a>block boxes</a> that establish an <a>independent formatting context</a>
 			have a used 'display' of ''flow-root'',