Add default handler for '+static/*' for css/etc

The +static mapping didn't work in tomcat, add
a default handler to make sure that the +static
directory is accessible and the css is loaded
correctly

Change-Id: Ia1018ebbe83a2ce757f9186d071dd758d6f036b4

gitiles-war/src/main/webapp/WEB-INF/web.xml

diff --git a/gitiles-war/src/main/webapp/WEB-INF/web.xml b/gitiles-war/src/main/webapp/WEB-INF/web.xml
index b4ad57d..bffacb5 100644
--- a/gitiles-war/src/main/webapp/WEB-INF/web.xml
+++ b/gitiles-war/src/main/webapp/WEB-INF/web.xml
@@ -29,6 +29,11 @@
   </servlet>
 
   <servlet-mapping>
+    <servlet-name>default</servlet-name>
+    <url-pattern>/+static/*</url-pattern>
+  </servlet-mapping>
+
+  <servlet-mapping>
     <servlet-name>gitiles</servlet-name>
     <url-pattern>/*</url-pattern>
   </servlet-mapping>