Ensure metadata message pre's are rendered with the correct monospace font.

Change-Id: I9efb277b7b373d5d7ba6336fec0ea1db1dcc89b0
diff --git a/gitiles-servlet/src/main/resources/com/google/gitiles/templates/LogDetail.soy b/gitiles-servlet/src/main/resources/com/google/gitiles/templates/LogDetail.soy
index 9e7c21b..015b88a 100644
--- a/gitiles-servlet/src/main/resources/com/google/gitiles/templates/LogDetail.soy
+++ b/gitiles-servlet/src/main/resources/com/google/gitiles/templates/LogDetail.soy
@@ -198,7 +198,7 @@
   </tr>
 </table>
 </div>
-<pre class="MetadataMessage">
+<pre class="u-pre u-monospace MetadataMessage">
   {$message}
 </pre>
 {/deltemplate}