[2020] The new melee should show two slashes on walls

The knife slashes for melee weapons should be consistent in visuals. For example, the prime melee is an axe and slashes downward, so the slashes on the walls go downward. Since the Oni knife has two blades, I don't see why it shouldn't show the corresponding visual effect when slashing. Obviously this shouldn't effect gameplay in any way, just visually.