[css-sizing] Fix previous version link.

Author: tabatkins

css-sizing/Overview.bs

@@ -9,7 +9,7 @@ TR: http://www.w3.org/TR/css3-sizing/
 Editor: Tab Atkins, Google, http://xanthir.com/contact/
 Editor: fantasai, Mozilla, http://fantasai.inkedblade.net/contact/
 !Issue Tracking: <a href="https://www.w3.org/Bugs/Public/buglist.cgi?product=CSS&amp;component=Sizing&amp;resolution=---">W3C Bugzilla</a>
-Previous version: http://www.w3.org/TR/2012/WD-css3-sizing-20120927/">http://www.w3.org/TR/2012/WD-css3-sizing-20120927/
+Previous version: http://www.w3.org/TR/2012/WD-css3-sizing-20120927/
 Abstract: This module extends the CSS sizing properties with keywords that represent content-based "intrinsic" sizes and context-based "extrinsic" sizes, allowing CSS to more easily describe boxes that fit their content or fit into a particular layout context.
 Link Defaults: css21 (property) min-width/min-height/max-width/max-height, css21 (dfn) containing block/initial containing block/block container box
 Ignored Terms: block-level box