Fixed threaded messages actions

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -263,7 +263,7 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
             final TupleMessageEx message = getItem(pos);
 
             PopupMenu popupMenu = new PopupMenu(context, itemView);
-            if (!EntityFolder.OUTBOX.equals(message.folderType)) {
+            if (!message.threaded && !EntityFolder.OUTBOX.equals(message.folderType)) {
                 popupMenu.getMenu().add(Menu.NONE, action_flag, 1, message.ui_flagged ? R.string.title_unflag : R.string.title_flag);
                 popupMenu.getMenu().add(Menu.NONE, action_seen, 2, message.ui_seen ? R.string.title_unseen : R.string.title_seen);
             }

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -181,7 +181,7 @@ public class FragmentMessages extends FragmentEx {
                     return 0;
 
                 TupleMessageEx message = ((AdapterMessage) rvMessage.getAdapter()).getCurrentList().get(pos);
-                if (EntityFolder.OUTBOX.equals(message.folderType))
+                if (message.threaded || EntityFolder.OUTBOX.equals(message.folderType))
                     return 0;
 
                 return makeMovementFlags(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT);