Bug 12336: Author of reserved book is not displayed in opac-user.pl

Bug 12336: Author of reserved book is not displayed in opac-user.pl

This patch adds a line in opac-user.pl passing author info to opac-user.tt
Thanks to cait for helping me out and showing me how to solve this with half the amount of code.

Test plan:
* Reserve a book.
* Go to the opac and log in as the patron you reserved the book for.
* Apply the patch with change to opac-user.pl
* Revisit the opac and refresh it.
* See if author now shows up

Signed-off-by: Magnus Enger <digitalutvikling@gmail.com>
Created a hold. Author is not shown n the public catalogue before
applying the patch, but it does show after applying the patch. Way
to go, Viktor!

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>