[css-module] rm rel=previous, it means prev in a sequence, not previous *version*

Author: Tantek Çelik

css-module/Overview.src.html

@@ -48,7 +48,7 @@ <h2 class="no-num no-toc">[LONGSTATUS] <time class="dt-updated" datetime="[CDATE
     (<a href="https://dvcs.w3.org/hg/csswg/log/tip/[SHORTNAME]/Overview.src.html">change log</a>)
 
   <dt>Previous version:
-    <dd><a rel="previous" href="http://www.w3.org/PreviousVersionURI">
+    <dd><a href="http://www.w3.org/PreviousVersionURI">
     http://www.w3.org/PreviousVersionURI</a>
 
   <dt>Issue Tracking:</dt>