Remove skin penetration from curare

[Superlagg]

While it does make the chem an absolute nightmare to go up against (one click with a beaker and you're done), it is one of the staple murder options Botany has.

Though cyanide also penetrates skin, they can make as much amanitin as they want, and can make tomato clusterbombs in the first five minutes of the round. Maybe they can stand to have one less ultramurder option.