IBX-8357: Fixed item export

[reithor]

Question	Answer
JIRA issue	IBX-8357
Type	bug
Target Ibexa DXP version	v3.3.38
BC breaks	no
Doc needed	no

See IBX-8357.
Issue is only on 3.3.

For QA:
Error can be reproduced with fictional settings for:

PERSONALIZATION_CUSTOMER_ID={...}
PERSONALIZATION_LICENSE_KEY={...}
PERSONALIZATION_HOST_URI=https://{...}

Then - after fix - initial error is gone and 'expected error' is shown :

In EzRecommendationClient.php line 161:
  Client error: `POST https://....` resulted in a `401 Unauthorized` response:

Checklist:

• Provided PR description.
• Tested the solution manually.
• Provided automated test coverage.
• Checked that target branch is set correctly (master for features, the oldest supported for bugs).
• Ran PHP CS Fixer for new PHP code (use $ composer fix-cs).
• Asked for a review (ping @ezsystems/php-dev-team).

[tomaszszopinski]

QA approved on IbexaDXP 3.3 experience.