Fix nav closing tag

Change-Id: I751ff56cbbd4c10e277346616e4b9e5a4cddf367

resources/com/google/gitiles/templates/Doc.soy

diff --git a/resources/com/google/gitiles/templates/Doc.soy b/resources/com/google/gitiles/templates/Doc.soy
index 426ba15..8d73789 100644
--- a/resources/com/google/gitiles/templates/Doc.soy
+++ b/resources/com/google/gitiles/templates/Doc.soy
@@ -54,7 +54,7 @@
     {if $navbarHtml}
       <nav class="Header-nav" role="navigation">
         {$navbarHtml}
-      </div>
+      </nav>
     {/if}
   </header>
   <div class="Site-content Site-Content--markdown">