[BOK] Patron of the Akki causes null pointer exception when attempting to offer a token

Server error log:
`INFO 2022-02-24 21:07:15,657
Stack before error 1:
Cast Patron of the Akki
=>[GAME d22d311b-ab2d-43d8-8e97-468ab05b741e] GameImpl.playPriority
FATAL 2022-02-24 21:08:21,480 Game exception gameId: d22d311b-ab2d-43d8-8e97-468ab05b741e =>[GAME d22d311b-ab2d-43d8-8e97-468ab05b741e] GameImpl.playPriority
java.lang.NullPointerException
at mage.abilities.keyword.OfferingCostReductionEffect.apply(OfferingAbility.java:228)
at mage.abilities.effects.ContinuousEffects.costModification(ContinuousEffects.java:741)
at mage.abilities.AbilityImpl.activate(AbilityImpl.java:392)
at mage.abilities.ActivatedAbilityImpl.activate(ActivatedAbilityImpl.java:259)
at mage.game.stack.Spell.activate(Spell.java:139)
at mage.players.PlayerImpl.cast(PlayerImpl.java:1236)
at mage.players.PlayerImpl.activateAbility(PlayerImpl.java:1492)
at mage.player.human.HumanPlayer.activateAbility(HumanPlayer.java:2083)
at mage.player.human.HumanPlayer.activateAbility(HumanPlayer.java:2106)
at mage.player.human.HumanPlayer.priority(HumanPlayer.java:1191)
at mage.game.GameImpl.playPriority(GameImpl.java:1535)
at mage.game.turn.Step.priority(Step.java:61)
at mage.game.turn.Phase.playStep(Phase.java:184)
at mage.game.turn.Phase.play(Phase.java:89)
at mage.game.turn.Turn.play(Turn.java:132)
at mage.game.GameImpl.playTurn(GameImpl.java:1060)
at mage.game.GameImpl.play(GameImpl.java:970)
at mage.game.GameImpl.start(GameImpl.java:946)
at mage.server.game.GameWorker.call(GameWorker.java:34)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
`