Bug 13685: Sorting by author in opac reading history

Bug 13685: Sorting by author in opac reading history

opac-readingrecord.pl was actually already set up to do this, the option
to sort by author was just not put into the tt file. This patch adds
that.

To test:
1) Log into OPAC, go to your reading history
2) Confirm that 'Order by author' shows in the dropdown
3) Confirm it works as expected

Sponsored-by: Catalyst IT
Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>