[TASK] unserialize() without objects in impexp

Change-Id: I09d769584dc4389d0d6e0d2ffa3e8e1b0fa571ad
Resolves: #76327
Releases: master
Reviewed-on: https://review.typo3.org/48333


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>