NPE thrown when editing permissions

[gianluca-nitti]

The following stack trace was reported to be shown in the server after removing the cheat permission from the web interface. The operation, anyway, was performed properly.
Looks like something related to notifying a client of an event, but needs further investigation.

15:59:17.420 [main] INFO  o.t.p.i.ReadWriteStorageManager - Auto Saving - Snapshot created: Writing phase starts
15:59:24.800 [main] ERROR o.t.e.event.internal.EventSystemImpl - Failed to invoke event
java.lang.NullPointerException: null
	at org.terasology.web.resources.ResourceManager.onEvent(ResourceManager.java:179)
	at org.terasology.web.resources.base.RouterResource$1.onEvent(RouterResource.java:46)
	at org.terasology.web.resources.base.AbstractObservableResource.notifyEvent(AbstractObservableResource.java:38)
	at org.terasology.web.resources.console.ConsoleResource.onMessage(ConsoleResource.java:58)
	at org.terasology.web.resources.console.ConsoleResourceMethodAccess.invoke(Unknown Source)
	at org.terasology.entitySystem.event.internal.EventSystemImpl$ByteCodeEventHandlerInfo.invoke(EventSystemImpl.java:531)
	at org.terasology.entitySystem.event.internal.EventSystemImpl.sendStandardEvent(EventSystemImpl.java:291)
	at org.terasology.entitySystem.event.internal.EventSystemImpl.send(EventSystemImpl.java:282)
	at org.terasology.entitySystem.entity.internal.BaseEntityRef.send(BaseEntityRef.java:204)
	at org.terasology.logic.console.ConsoleImpl.execute(ConsoleImpl.java:250)
	at org.terasology.logic.console.ConsoleSystem.onCommand(ConsoleSystem.java:79)
	at org.terasology.logic.console.ConsoleSystemMethodAccess.invoke(Unknown Source)
	at org.terasology.entitySystem.event.internal.EventSystemImpl$ByteCodeEventHandlerInfo.invoke(EventSystemImpl.java:531)
	at org.terasology.entitySystem.event.internal.EventSystemImpl.sendStandardEvent(EventSystemImpl.java:291)
	at org.terasology.entitySystem.event.internal.EventSystemImpl.send(EventSystemImpl.java:282)
	at org.terasology.entitySystem.entity.internal.BaseEntityRef.send(BaseEntityRef.java:204)
	at org.terasology.network.internal.NetClient.processEvents(NetClient.java:533)
	at org.terasology.network.internal.NetClient.processReceivedMessages(NetClient.java:429)
	at org.terasology.network.internal.NetClient.update(NetClient.java:236)
	at org.terasology.network.internal.NetworkSystemImpl.update(NetworkSystemImpl.java:319)
	at org.terasology.engine.subsystem.common.NetworkSubsystem.preUpdate(NetworkSubsystem.java:52)
	at org.terasology.engine.TerasologyEngine.tick(TerasologyEngine.java:451)
	at org.terasology.engine.TerasologyEngine.mainLoop(TerasologyEngine.java:421)
	at org.terasology.engine.TerasologyEngine.run(TerasologyEngine.java:397)
	at org.terasology.web.EngineRunner.runEngine(EngineRunner.java:66)
	at org.terasology.web.ServerMain.main(ServerMain.java:119)
16:00:17.425 [main] INFO  o.t.p.i.ReadWriteStorageManager - Auto Saving - Creating game snapshot
16:00:17.427 [main] INFO  o.t.p.i.ReadWriteStorageManager - Auto Saving - Snapshot created: Writing phase starts