[API] `Scheduler.answerCard` NoSuchElementException: List is empty.

[david-allison]

2.24.0alpha13

https://ankidroid.org/acra/app/1/bug/396845/report/db62bb7a-bd8d-4f97-93be-00fc4f7ca9fe

java.util.NoSuchElementException: List is empty.
	at kotlin.collections.CollectionsKt___CollectionsKt.first(_Collections.kt:222)
	at com.ichi2.anki.libanki.sched.Scheduler.answerCard(Scheduler.kt:156)
	at com.ichi2.anki.provider.CardContentProvider.answerCard(CardContentProvider.kt:1226)
	at com.ichi2.anki.provider.CardContentProvider.update(CardContentProvider.kt:706)
	at android.content.ContentProvider.update(ContentProvider.java:2135)
	at android.content.ContentProvider$Transport.update(ContentProvider.java:582)
	at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:243)
	at android.os.Binder.execTransactInternal(Binder.java:1457)
	at android.os.Binder.execTransact(Binder.java:1401)