Fix Service Book URL

index.html

@@ -59,7 +59,7 @@
         <ul class="nav nav-sidebar">
           <li><a href="https://quality.mozilla.org/teams/test-engineering/">About Firefox Test Engineering</a></li>
           <li><a href="http://firefox-test-engineering.readthedocs.io/">Documentation</a></li>
-          <li><a href="http://servicebook.dev.mozaws.net/">Service Book</a></li>
+          <li><a href="https://servicebook.stage.mozaws.net/">Service Book</a></li>
           <li><a href="https://wiki.mozilla.org/TestEngineering">Wiki</a></li>
         </ul>
         <ul class="nav nav-sidebar">