Remove the chance of 0 Scar/Targa helm drop

It feels a little cruel that there is a chance that a helm will not drop. Scar/Targa aren't really sought after for their drops or exp. According to this chart in an old post regarding bosses, Scar/Targa have the worst hp:exp ratio. I suggest updating the chance of a helm drop from 0-4 to 1-4.

This will benefit:

-buyers who are patiently wait for a helm to drop
-sellers who cannot charge buyers if a helm does not drop
-helm farmers that are trying to min-max their helm instead of pursuing more exp-efficient bosses