fix crash in the ControllerManager::updateAllControllers when mControllers is changed while iterating over it

[Altren]

More details: https://forums.ogre3d.org/viewtopic.php?t=97339

[paroj]

can you elaborate on the use-case where you need this?

Also, we typically use this pattern to allow remove/ add during iteration:

ogre/OgreMain/src/OgreSceneManager.cpp

Lines 2418 to 2419 in d111e9d

	ListenerList listenersCopy = mListeners;
	for (auto *l : listenersCopy)

[Altren]

I do not know why this crash started happening and how to reproduce it on a minimal example

[paroj]

crashing was likely introduced by f7cd9dd hence this is fixing a regression