Fix deleting a comment doesn't pop back to timeline but stays on post thread view

lib/controls/timeline/flattened_tree_entry_control.dart

@@ -387,7 +387,7 @@ class _StatusControlState extends ConsumerState<FlattenedTreeEntryControl> {
           .deleteEntryById(item.timelineEntry.id)
           .match(onSuccess: (_) {
         isProcessing = false;
-        if (context.canPop()) {
+        if (isPost && context.canPop()) {
           context.pop();
         }
       }, onError: (e) {