Bug 16823 - Comment out koha-rebuild-zebra in koha-common.cron.d

Bug 16823 - Comment out koha-rebuild-zebra in koha-common.cron.d

Bug 16190 enabled the indexer daemon by default for package installations.
This means that it is no longer necessary to set up koha-rebuild-zebra as
a cron job. This patch comments it out, so that people who might run into
bug 16814 can easily activate the cronjob again after de-activating the
indexer daemon.

To test:
Just read the diff and check that it makes sense.

Signed-off-by: Srdjan <srdjan@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>