fix: possibly fixes a crash where inReplyToId is null in a ThreadFragment

cc: @sk22

Btw check the commit before this one, because there is a fix that applies for Megalodon there as well

mastodon/src/main/java/org/joinmastodon/android/fragments/ThreadFragment.java

@@ -315,7 +315,7 @@ public class ThreadFragment extends StatusListFragment implements ProvidesAssist
 					// descendant neighbor
 					Optional
 							.ofNullable(count > index + 1 ? statuses.get(index + 1) : null)
-							.filter(s -> s.inReplyToId.equals(current.id))
+							.filter(s -> current.id.equals(s.inReplyToId))
 							.orElse(null),
 					// ancestoring neighbor
 					Optional.ofNullable(index > 0 ? ancestry.get(index - 1) : null)