They are there because of the unhelpful habit of vespucci (android mapping app) of copying tags from previous edits into new edits. Those two tags came from a location I had edited previously (https://www.openstreetmap.org/changeset/154573498)
 
I have not worked out exactly what sequence of clicks/events causes these spurious tags to appear 4 changesets later in a different edit. But it has happened to me before. 

So thanks for spotting that.
Now fixed. 