Changing a color to a copied palette are applied to the original palette

[AngeleAkane]

Pixelorama version:

1.1.2-dev

Where did you download Pixelorama from?

OS/device including version:

Windows 10

Issue description:

The changes applied to a palette whose preset comes from an existing one allows to, when editing the copy, the existing one is also edited. This happens only with "double-click editing". Adding or deleting doesn't apply to other palettes.

Steps to reproduce:

1. Create a palette
2. Add a color
3. Create another palette BUT in PRESET select FROM CURRENT PALETTE
4. Edit the color with a double click.

Once changed, go to the earlier palette to notice the difference.

[OverloadedOrama]

Should be fixed in 8ac4060, thanks again!