[x/blog] go.blog: fix Go Twitter link

R=golang-dev, dave
https://golang.org/cl/30000043
X-Blog-Commit: dbdc6c111ff558d964c7fc7d17eb538aa323809b

blog/template/root.tmpl

@@ -98,7 +98,7 @@
 	<li><a href='http://groups.google.com/group/golang-nuts'>Go Mailing List</a></li>
 	<li><a href='https://plus.google.com/101406623878176903605'>Go on Google+</a></li>
 	<li><a href='https://plus.google.com/112164155169467723645/posts'>Go+ Community</a></li>
-	<li><a href='http://twitter.com/go_nuts'>Go on Twitter</a></li>
+	<li><a href='http://twitter.com/golang'>Go on Twitter</a></li>
 	</ul>
 	
 	<h4>Keep up with Google Developers</h4>