URLrewriter: status page throws NPE when no root directory has ever been created.

When an empty project is started, requesting the status page throws an NPE:

[WARNING] [talledLocalContainer] 11-Jul-2012 18:42:56 org.apache.catalina.core.StandardWrapperValve invoke
[WARNING] [talledLocalContainer] SEVERE: Servlet.service() for servlet default threw exception
[WARNING] [talledLocalContainer] java.lang.NullPointerException
[WARNING] [talledLocalContainer] at org.tuckey.web.filters.urlrewrite.Status.showHeader(Status.java:314)
[WARNING] [talledLocalContainer] at org.tuckey.web.filters.urlrewrite.Status.displayStatusInContainer(Status.java:78)
[WARNING] [talledLocalContainer] at org.onehippo.forge.rewriting.HippoRewriteFilter.showStatus(HippoRewriteFilter.java:324)
[WARNING] [talledLocalContainer] at org.onehippo.forge.rewriting.HippoRewriteFilter.doFilter(HippoRewriteFilter.java:248)
[WARNING] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
[WARNING] [talledLocalContainer] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
[WARNING] [talledLocalContainer] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
[WARNING] [talledLocalContainer] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
[WARNING] [talledLocalContainer] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:470)
[WARNING] [talledLocalContainer] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
[WARNING] [talledLocalContainer] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
[WARNING] [talledLocalContainer] at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:589)
[WARNING] [talledLocalContainer] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
[WARNING] [talledLocalContainer] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:291)
[WARNING] [talledLocalContainer] at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
[WARNING] [talledLocalContainer] at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
[WARNING] [talledLocalContainer] at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
[WARNING] [talledLocalContainer] at java.lang.Thread.run(Thread.java:662)

When a root folder has been created, the status page requested, and the folder deleted again, it shows correctly that there are 0 rules.