Observed repeated NPEs printed during shutdown.

java.lang.NullPointerException
	at hudson.model.listeners.RunListener.all(RunListener.java:216)
	at hudson.model.listeners.RunListener.fireFinalized(RunListener.java:196)
	…

core/src/main/java/hudson/model/listeners/RunListener.java

@@ -204,6 +204,9 @@ public abstract class RunListener<R extends Run> implements ExtensionPoint {
      * Fires the {@link #onFinalized(Run)} event.
      */
     public static void fireFinalized(Run r) {
+        if (Jenkins.getInstance() == null) {
+            return;
+        }
         for (RunListener l : all()) {
             if(l.targetType.isInstance(r))
                 try {