bug#6312: 24.0.50; recursive copy message: one tree, not one file

[jidanni]

After answering yes to
  Recursive copies of /mnt/extra/各廠無線網卡驅動? (yes or no)
(which by the way, does not end up in *Messages*, darn it),
we see
  Copy: 1 of 1
  Copy: 1 file

Huh? Only one file?
We check and indeed the whole tree has been copied. Many files.
So say, "1 tree" if you must, but not "1 file". Or say how many trees
and how many files total, perhaps.