Switch to side-by-side view

--- a/Allura/allura/templates/widgets/repo/commit.html
+++ b/Allura/allura/templates/widgets/repo/commit.html
@@ -29,7 +29,7 @@
       <td>change</td>
       <td>
         <a href="./tree/{{h.really_unicode(diff)}}">{{h.really_unicode(diff)}}</a>
-        <a href="./tree/{{h.really_unicode(diff)}}?diff={{prev[0].object_id}}">(diff)</a>
+        <a href="./tree/{{h.really_unicode(diff)}}?diff={{prev[0]._id}}">(diff)</a>
       </td>
     </tr>
     {% endfor %}{% for diff in commit.diffs.copied %}