fix: Incorrect closing quote

Author: nschonni

css-break-3/Overview.bs

@@ -1196,7 +1196,7 @@ Transforms, Positioning, and Pagination</h3>
 Changes</h2>
 
   <p>The following significant changes were made since the
-    <a href="https://www.w3.org/TR/2018/CR-css-break-3-20181204/'>4 December 2018 Candidate Recommendation</a>:
+    <a href="https://www.w3.org/TR/2018/CR-css-break-3-20181204/">4 December 2018 Candidate Recommendation</a>:
 
   <ul>
     <li id="bugfix-2018-drop-cloned">