store: sort messages even when a filter is applied

Sort the message list even when a filter is applied according to the
sort criteria given by the sort command.

Currently, the sort command has no effect when a filter is in use.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

lib/msgstore.go

@@ -198,6 +198,7 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		}
 		store.Messages = newMap
 		store.uids = msg.Uids
+		sort.SortBy(store.filtered, store.uids)
 		update = true
 	case *types.DirectoryThreaded:
 		var uids []uint32