Rearranging folder crash

[geekygecko]

There is a crash in Firebase when a user is rearranging folders.

Fatal Exception: java.lang.ArrayIndexOutOfBoundsException: length=89; index=-1
       at java.util.ArrayList.get(ArrayList.java:439)
       at java.util.Collections.swap(Collections.java:544)
       at au.com.shiftyjelly.pocketcasts.podcasts.viewmodel.PodcastsViewModel.moveFolderItem(PodcastsViewModel.kt:193)
       at au.com.shiftyjelly.pocketcasts.podcasts.view.podcasts.PodcastsFragment.onPodcastMove(PodcastsFragment.kt:312)
       at au.com.shiftyjelly.pocketcasts.views.adapter.PodcastTouchCallback.onMove(PodcastTouchCallback.kt:27)
       at androidx.recyclerview.widget.ItemTouchHelper.moveIfNecessary(ItemTouchHelper.java:885)
       at androidx.recyclerview.widget.ItemTouchHelper$2.onTouchEvent(ItemTouchHelper.java:389)
       at androidx.recyclerview.widget.RecyclerView.dispatchToOnItemTouchListeners(RecyclerView.java:3259)
       at androidx.recyclerview.widget.RecyclerView.onTouchEvent(RecyclerView.java:3421)