Save scene as branch disconnects all signals to and from the branch

[Jattmackson]

Godot version:
3.2.3

OS/device including version:
GTX 1060 6GB, gles 3.0

Issue description:
When saving a branch as a scene you would expect the signals connected to (at least) the root of that branch to remain connected
When saving as branch all signals to and from that branch are disconnected.

Steps to reproduce:
Create a button.
Add a child with a script.
Connect the button's pressed signal to it's child (e.g make it print "hello world")
Run the program, prints hello world when the button is pressed
Save the child as a branch
Run the program, pressing the button does nothing.

Minimal reproduction project:
SignalDisconnect.zip

(This is the project before saving branch as scene, save the child as branch and it disconnects the signal)