Patch: wording change

[Andrew Ash]

A user at https://launchpad.net/ubuntu/+source/amarok/+bug/59346
suggested that in the collection statistics "Listening since five
weeks ago" didn't flow very well, and suggested changing it.  I've
chosen "First played five weeks ago" since that seems more accurate to
the information being presented.

The same bug had been submitted to the KDE bug tracker at
http://bugs.kde.org/show_bug.cgi?id=131727 where I attached a patch.
Hopefully this isn't too late for the string freeze.

Thanks,
Andrew Ash