property xmpp.pubsub.create.anyone is inverted
Forum user points out that the intuitive meaning of this property is inverted.
xmpp.pubsub.create.anyone = true does not mean that anybody can create pubsub nodes
Well, this is all pretty weird.
So setting xmpp.pubsub.create.anyone to true does indeed mean that anyone cannot create a node - it's only the admins. So that's wrong. But it seems like nobody's noticed before...