Properties of inherited nodes in open sub-inherited scenes do not update

[homchom]

Godot version: 3.2.2.stable

OS/device including version: Dell Inspiron 13-7378, Windows 10 Home v1903

Issue description: If the property of a node is changed in a scene, it updates properly in all top-level inherited scenes, but not currently open scenes that are inherited from those scenes. Closing and reopening the scene, or clicking the "reset" icon next to the property in the inspector, fixes this issue. This is possibly related to #7984, but it was marked as closed/fixed.

Steps to reproduce:

1. Create a new scene A with a ColorRect node. Change the color to anything.
2. Create a new inherited scene B (inherited from A).
3. Create a new inherited scene C (inherited from B).
4. Open all 3 scenes at once. Keep them open.
5. Change the color of the ColorRect in scene A again. Save the scene.
6. Observe that the color has updated in scene B, but not scene C.

Minimal reproduction project: sub-inherited scene bug.zip
(Scene A is 'Menu', Scene B is 'Submenu', and Scene C is 'ExampleMenu'. Change the ColorRect color in the 'Menu' scene with 'Submenu' and 'ExampleMenu' open to observe the bug.)