Avoid warnings in the carrier sync

[jokesterfr]

Calling the carriers sync causes warning rejected as invalid JSON on the cloud end.

❯ curl -i 'https://8c85-88-162-75-65.eu.ngrok.io/index.php?fc=module&module=ps_eventbus&controller=apiCarriers&job_id=0a47433a1b3ac3e8cd89c91b58ef801e840e2958&limit=50&lang_iso=en'
HTTP/2 201 
cache-control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
content-type: application/json;charset=utf-8
date: Wed, 18 Jan 2023 21:27:01 GMT
ngrok-trace-id: dc0383bbc678038ff90001fbeb7a41a5
server: Apache/2.4.54 (Debian)
set-cookie: PrestaShop-d691e2ea23ff4e041cab61f0bee01f0a=def502003e9a1bf6bc7cbf125d7aed2e35837913637c2cff76a0df1cfebee0d19cc56b720eff855957c3705e9ee8f7ab6a32394d4deeb54c0327a90aa5cfcfa7fa6e7bd9bf8ced4aa50d41c5c0999a98acfb246150e9eea1220b79a25166b35fef3af9e84e2749ed49a2b1e44cea726393decfa3276cda9b9b9312e272319096e7db2ed8f013dc19b557e1d8327ba9c38b83bdf5768d3bc9d2fee5452b8e386b2118d8f7ffd65c1e0474f210bbfe96b2bb46fac5cbbe13f7fe4f07377854d95e83d81eebb27b; expires=Tue, 07-Feb-2023 21:27:01 GMT; Max-Age=1727999; path=/; domain=8c85-88-162-75-65.eu.ngrok.io; secure; HttpOnly; SameSite=Lax
content-length: 762<br />
<b>Warning</b>:  Array to string conversion in <b>/var/www/html/modules/ps_eventbus/src/DTO/Carrier.php</b> on line <b>724</b><br />
<br />
<b>Warning</b>:  Array to string conversion in <b>/var/www/html/modules/ps_eventbus/src/DTO/Carrier.php</b> on line <b>724</b><br />
<br />
<b>Warning</b>:  Array to string conversion in <b>/var/www/html/modules/ps_eventbus/src/DTO/Carrier.php</b> on line <b>724</b><br />
{"job_id":"0a47433a1b3ac3e8cd89c91b58ef801e840e2958","object_type":"carriers","total_objects":17,"has_remaining_objects":false,"remaining_objects":0,"md5":"ff890720f05c9d91abb39fafe567774f","status":true,"httpCode":201,"body":{"status":"success"},"upload_url":"http://cloudsync-collector:3000/upload/0a47433a1b3ac3e8cd89c91b58ef801e840e2958"}%