It will be the same baptism.
One of them will be dated 1686, as February came before the end of the year in April at this point in time, and the other will be because somebody has 'modernised' the date, and said that Feb was in 1687 (starting the new year Jan 1st as we do now, instead of in April as they did then).
That's why the old transcription of the register you posted gives the date as it would have been in the register - 1686. I suspect if you go a little further down the page, you'll see it change to 1687.
