[Lua] Fixed discrepancy in distribution of pup heads.

[CatsEyeXI]

I affirm:

• [x] I understand that if I do not agree to the following points by completing the checkboxes my PR will be ignored.
• [x] I have read and understood the Contributing Guide and the Code of Conduct.
• [x] I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

We have received dozens of reports for players receiving the WHM PUP head instead of the BLM one. This corrects that issue. Closes #3338

Steps to test these changes

Approach Ghatsad NPC in Aht Urhgan and trade him the corresponding items.

[CatsEyeXI]

hey, just wanted to touch base on this, is there anything we can help with to get this merged? we've got a band aid in place at the moment, but this is negatively impacting the playability of PUP.

[Xaver-DaRed]

Dont close this, pls