No harm done! All you did was propose the merge. You didn't actually merge the profiles.
When an erroneous merge proposal is created, it can be removed by simply changing it to an unmerged match or a rejected match. Then it can be removed (or kept if there's reason to think it should be an unmerged match or a rejected match).
I changed this one to a rejected match.
Now you can propose the merge you intended. Because it's so easy to enter the wrong profile number, it's a good idea to COMPARE the two profiles before proposing the merge.