Fix oddity in how last import time was being displayed

For the value "2014-09-30 11:59:34" it was displaying "on 30/9/14"
instead of "1 month, 5 days ago". Seems like a bug, but bizarrely both
kinds of outputs are mentioned in the documentation at
http://book.cakephp.org/2.0/en/core-libraries/helpers/time.html.