Fix Rumble spell slowness level

Plugins/Nautilus.Game.Arcade/src/nautilus/game/arcade/game/games/wizards/spells/SpellRumble.java

@@ -278,10 +278,12 @@ public class SpellRumble extends Spell implements SpellClickBlock, SpellClick
 
 										if (entity instanceof Player)
 										{
+											// Why does Slowing by 2 apply slowness 1?  The world may never know.
+											// As such, we subtract one from the spellLevel and ask no more questions
 											Wizards.getArcadeManager()
 													.GetCondition()
 													.Factory()
-													.Slow("Rumble", (LivingEntity) entity, player, 3, spellLevel, false, false,
+													.Slow("Rumble", (LivingEntity) entity, player, 3, spellLevel-1, false, false,
 															false, false);
 										}
 									}