Fix invalid nozzle_type undefined for 'Anycubic Kobra 2 0.4 nozzle' system machine

[krissrex]

The correct value is undefine.

Related to a comment in #3991 (comment)

Description

Filament loading will crash if this value is undefined instead of undefine.

Screenshots/Recordings/Graphs

[error]	2024-04-26 19:34:05.440249[Thread 0x00003784]:Slic3r::ConfigBase::load_from_json: parse C:\Users\Kristian\AppData\Roaming\OrcaSlicer\system/Anycubic/machine/Anycubic Kobra 2 0.4 nozzle.json got a generic exception, reason = Invalid value provided for parameter nozzle_type: undefined
[error]	2024-04-26 19:34:05.440249[Thread 0x00003784]:Slic3r::PresetBundle::load_vendor_configs_from_json::<lambda_2e6da75a0232aea84d16ba067e6fa242>::operator (): load config file C:\Users\Kristian\AppData\Roaming\OrcaSlicer\system/Anycubic/machine/Anycubic Kobra 2 0.4 nozzle.json Failed!
[error]	2024-04-26 19:34:05.440249[Thread 0x00003784]:Slic3r::PresetBundle::load_vendor_configs_from_json, got error when parse printer setting from C:\Users\Kristian\AppData\Roaming\OrcaSlicer\system/Anycubic/machine/Anycubic Kobra 2 0.4 nozzle.json

Tests

Edited the file on my machine directly. It works.

[krissrex]

Note that I do not think this solves 3991. I just discovered the same symptoms, and started my troubleshooting there.
The provided logs of 3991 do not contain the same error as mine.

[SoftFever]

LGTM

[SoftFever]

Note that I do not think this solves 3991. I just discovered the same symptoms, and started my troubleshooting there. The provided logs of 3991 do not contain the same error as mine.

Noted.
Thanks for the fix!