"Variable already exists" warning appears when changing scoping of existing variable

[JJ3141592]

Just a strange bug in the editor. It gives a warning that ends up doing nothing.

Steps to reproduce:

1. Create a variable
2. Right-click the variable and choose 'rename or edit variable'
3. Delete a character from the variable name and add it back so the name isn't different.
4. Change the scope of the variable

At this point, clicking 'OK' will result in a warning saying that the variable already exists. The scope will change, as expected. No functionality is affected, however the unexpected warning box is annoying.

[GarboMuffin]

This seems to be a Scratch bug in the rename variable prompt