Fixed removing node from supernode after layout transition when automaticallyManagesSubnodes is disabled. In case if developer prefer to manage subnodes by himself then he wants to be sure that stack will not change automatically.
We have to check in this case if the supernode of the subnode is indeed the _node that executes a layout transition. It can happen that a node already did a layout transition and added this subnode, in this case the subnode would would be removed from the new node instead of _node.