Bug 16248: ModZebra doesn't update zebraqueue if ES is enabled

Bug 16248: ModZebra doesn't update zebraqueue if ES is enabled

The zebraqueue table should still be populated with updates if ES is enabled, so
the Zebra indexer keeps the Z39.50/SRU indexes up to date.

To test:
- Set SearchEngine = Elasticsearch
- Watch for zebraqueue changes
  $ watch -n 0.5 'echo "SELECT COUNT(*) FROM zebraqueue WHERE done=0" | sudo koha-mysql kohadev'
- Call touch_all_biblios.pl to simulate record changes
  $ sudo koha-shell kohadev ; cd kohaclone
  $ perl misc/maintenance/touch_all_biblios.pl -v
=> FAIL: Notice the watch is not changing the number of records to be indexed.
- Apply the patch
- Call touch_all_biblios.pl to simulate record changes
  $ sudo koha-shell kohadev ; cd kohaclone
  $ perl misc/maintenance/touch_all_biblios.pl -v
=> SUCCESS: The count raises (more than 0) and the zebra indexer picks the updates.
- Sign off

Signed-off-by: Chris <chrisc@catalyst.net.nz>
Signed-off-by: Jesse Weaver <jweaver@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>