fix: 'effect' action gives an unwanted extra level

Author: Fritx22

src/main/java/me/zetastormy/akropolis/action/actions/PotionEffectAction.java

@@ -43,7 +43,7 @@ public void execute(AkropolisPlugin plugin, Player player, String data) {
 
         try {
             xpotion.ifPresent(p -> {
-                PotionEffect potionEffect = p.buildPotionEffect(1000000, Integer.parseInt(args[1]) - 1);
+                PotionEffect potionEffect = p.buildPotionEffect(1000000, Integer.parseInt(args[1]));
 
                 if (potionEffect == null) throw new IllegalStateException();