"/bossbar set players" error message wrong when ran on boss bars with empty player list

The bug

When running /bossbar set boss:bar players while the player list of that boss bar is already empty, the following error feedback text is printed in chat:

Nothing changed. Those players are already on the bossbar with nobody to add or remove

This is wrong. The command specified no players so the feedback text shouldn't mention "those players".

How to reproduce

1. /bossbar add boss:bar ""
2. /bossbar set boss:bar players