changed alien neurotoxin to bio type projectile (which means it's stopped by protective gear like biosuits), fixed a runtime

Signed-off-by: Cael_Aislinn <cael_aislinn@yahoo.com.au>

code/modules/projectiles/projectile/special.dm

@@ -122,4 +122,12 @@
 		else if (istype(target, /mob/living/carbon/))
 			M.show_message("\blue The radiation beam dissipates harmlessly through your body.")
 		else
-			return 1
+			return 1
+
+/obj/item/projectile/neurotoxin
+	name = "neurotoxin"
+	icon_state = "toxin"
+	damage = 5
+	damage_type = TOX
+	weaken = 5
+	flag = "bio"