Configuration watch thread causes Tomcat memory leak

While investigating LOG4J2-1159 I found that Tomcat (7.0.50) now gives this output when I shut it down while the test webapp is deployed:

SEVERE: The web application [/threadlocal] appears to have started a thread named [pool-2-thread-1] but has failed to stop it. This is very likely to create a memory leak.

This thread is probably the ScheduledExecutor that is now started if monitorInterval > 0. Still checking why the app is not stopped() and the executor is not shut down...