I would like to see this. In Johnson's dictionary, he cites the person who used the word thusly. Perhaps OED is citing a usage traceable to Switzerland. After all, the Swiss were using the word in that manner since 1370.
I keep pointing out that no other nation in the world referred to their members as "citizens." All the rest called them "Subjects" or "Sujets" in French.
The simple fact remains, the normal manner of referring to membership in a state for that time period was "Subjects."