[css-backgrounds-3] Fix double slash in URL

Author: fantasai

css-backgrounds-3/Overview.html

@@ -210,7 +210,7 @@ <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="cont
      <dt>Editor's Draft:
      <dd><a href="https://drafts.csswg.org/css-backgrounds/">https://drafts.csswg.org/css-backgrounds/</a>
      <dt>Previous Version:
-     <dd><a href="https://www.w3.org/TR/2014/CR-css3-background-20140909//" rel="prev">https://www.w3.org/TR/2014/CR-css3-background-20140909//</a>
+     <dd><a href="https://www.w3.org/TR/2014/CR-css3-background-20140909/" rel="prev">https://www.w3.org/TR/2014/CR-css3-background-20140909/</a>
      <dt>Test Suite:
      <dd><a href="http://test.csswg.org/suites/css3-background/nightly-unstable/">http://test.csswg.org/suites/css3-background/nightly-unstable/</a>
      <dt class="editor">Editors:

css-backgrounds-3/Overview.src.html

@@ -10,7 +10,7 @@ <h1>CSS Backgrounds and Borders Module Level 3</h1>
 Group: csswg
 ED: https://drafts.csswg.org/css-backgrounds/
 TR: https://www.w3.org/TR/css-backgrounds-3/
-Previous version: https://www.w3.org/TR/2014/CR-css3-background-20140909//
+Previous version: https://www.w3.org/TR/2014/CR-css3-background-20140909/
 Editor: Bert Bos, W3C, bert@w3.org
 Editor: Elika J. Etemad / fantasai, Invited Expert, http://fantasai.inkedblade.net/contact, w3cid 35400
 Editor: Brad Kemper, Invited Expert, brad.kemper@gmail.com