Prefix is not changed in Cura 3.6 or 4.0

[Ghostkeeper]

When changing the prefix, the actual job name of the slice is not changed accordingly. These are my reproduction steps:

1. Go to Extensions -> Custom printjob prefix -> Set prefix
2. Change the prefix to {layer_height}x and confirm the dialogue.
3. Load a model (in my case "cube.stl")

Expected result:

• Print job is called 0.1x_cube.

Actual result:

• Print job is still called UMS5_cube.

This only reproduces in Cura 3.6 and 4.0. In 4.1+ it works fine. In 3.5 it crashes as per #4.

[fieldOfView]

Fixed in 561f4b7. Thanks for the extensive testing!