Incorrect Input Index When Removing The Input From Custom Node

The input removed the connection points are not re-indexed. So connected 'wires' stay on their places. That causing disconnection of the last wire as well as shift for every node that followed the one being removed.

Found in 4.19 CL# 4033788, 4.20 CL# 4302132, 4.21 CL# 4307852

1. Open the Editor
2. Create a Material and add a Custom node
3. Add 4 inputs to the Custom node
4. Connect anything to the input
5. Delete the third input

Results:
What was attached to the 4th input will be disconnected and attached to the 3rd

Expected:
What was attached tot he 4th input will stay connected and disconnect the 3rd input