This reverts commit 40f9914e.

Per Colin's report (confirmed by Mathieu and Julian):
  "I've had some problems with this patch. With it applied I found
  overdues for multiple users getting the same user's overdue message
  text, eg user 1 gets their correct message but users 2, 3 and 4
  get it as well. reverting the patch corrected this. I've not tracked
  down the cause as yet."