Bug 11344: Perldoc issues in misc/cronjobs/advance_notices.pl

Bug 11344: Perldoc issues in misc/cronjobs/advance_notices.pl

This patch removes the double ups in the perldoc of the above file,
     deleting the less clear double ups. The missing "-c" in OPTIONS
     appears to have been fixed in an earlier patch (it is there
             already).

Task Plan:
1. Run perldoc misc/cronjobs/advance_notices.pl in the terminal. Note
the double ups of NAME, SYNOPSIS, and DESCRIPTION
2. Apply the patch
3. Run the command again. The double ups should be gone, with the more
clear version of each of NAME, SYNOPSIS, and DESCRIPTION remaining.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>