Bug 29244: Add dialog class where missing in print-notices.tt

Bug 29244: Add dialog class where missing in print-notices.tt

The print notices template had it's own implimentation of a message
dialog. To make it consistent with other area's, we should add the
dialog class.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit d7e94ea0115ee6a5dfb732571b7a57d52ffe943d)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>