vitess.io: Changing to the logo with white border in the non-dev config (vitess.io) as well.

I forgot this in my earlier pull request.

vitess.io/_config.yml

@@ -2,7 +2,7 @@
 
 title: Vitess
 description: "Vitess is a database clustering system for horizontal scaling of MySQL."
-logo: vitess_logo.svg
+logo: vitess_logo_with_border.svg
 teaser: 400x250.gif
 locale: en_US
 url: http://vitess.io