[music select] problem when change rival in the opposite direction

[N-ISOGE]

歌の選択中、ライバルを選択しない状態で逆方向に行く時問題です。

Exception in thread "LWJGL Application" java.lang.ArrayIndexOutOfBoundsException: Index -2 out of bounds for length 2
at bms.player.beatoraja.skin.property.EventFactory$EventType.lambda$static$21(Unknown Source)
at bms.player.beatoraja.skin.property.EventFactory$2.exec(Unknown Source)
at bms.player.beatoraja.skin.property.Event.exec(Unknown Source)
at bms.player.beatoraja.skin.SkinObject.mousePressed(Unknown Source)
at bms.player.beatoraja.skin.Skin.mousePressed(Unknown Source)
at bms.player.beatoraja.MainController.render(Unknown Source)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:232)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:127)

Desktop.2021.12.22.-.23.31.16.04.mp4

[Chazoshtare]

I fixed this in a PR, choosing a previous rival while none was picked led to OutOfBoundsException.