Fix auto-correct for "Send feedback only if track armed"

[helgoboss]

The auto-correct feature for this checkbox was working wrong all this time. This checkbox is supposed to become automatically enabled when switching MIDI control input to "" and disabled when switching to a concrete device - because this is what users probably want in 90% of all cases. However, it was doing exactly the opposite! Since pre9 this is more severe because you don't immediately see this checkbox anymore.