Bug 34990: Add persistent header when sending msg to RabbitMQ

Test plan:
NOTE: It is very hard to add a Koha unit test for adding this
single header when communicating to RabbitMQ via Stomp plugin.
When we would mock the send, we are only testing if perl can
pass a hashref to a subroutine ;)

Do NOT yet apply this patch.
Make sure that RabbitMQ runs.
Stop the koha-worker for long_tasks:
  koha-worker --stop --queue long_tasks myclone
Stage a MARC file.
Check queues with rabbitmqctl list_queues.
Look for: koha_myclone-long_tasks 1  (at least 1)
Stop rabbitmq (something like /etc/init.d/rabbitmq-server stop)
Start rabbitmq (/etc/init.d/rabbitmq-server start)
Check queue again with with rabbitmqctl list_queues.
Look for: koha_myclone-long_tasks 0
Your messages have been gone.

Now apply this patch.
Reiterate the former steps. But note that you will still see
a non-empty queue in the last step:
koha_myclone-long_tasks 1 (at least 1)

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 5797f5095e)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>

Koha/BackgroundJob.pm

@@ -138,7 +138,8 @@ sub enqueue {
         # Picking a random id (memcached_namespace) from the config
         my $namespace = C4::Context->config('memcached_namespace');
         my $encoded_args = Encode::encode_utf8( $json_args ); # FIXME We should better leave this to Net::Stomp?
-        $conn->send_with_receipt( { destination => sprintf("/queue/%s-%s", $namespace, $job_queue), body => $encoded_args } )
+        my $destination = sprintf( "/queue/%s-%s", $namespace, $job_queue );
+        $conn->send_with_receipt( { destination => $destination, body => $encoded_args, persistent => 'true' } )
           or Koha::Exceptions::Exception->throw('Job has not been enqueued');
     } catch {
         $self->status('failed')->store;