When used as global Netty resources, ReactorResourceFactory creates and
sets those resources on Reactor's HttpResources directly.
When that ReactorResourceFactory bean is destroyed, those resources are
disposed but HttpResources still holds a reference to those and may try
to use them again.
This commit uses HttpResources to clear those resources and its
references to it, when the ReactorResourceFactory is treating those as
global.
Issue: SPR-17199
709b185177