[BUGFIX] Quick Edit triggers warnings of missing key uid

A see issue for details. Other parts of the core relay on the result of
the "broken" API call.

Fixes: #42845
Releases: 4.5, 4.6, 4.7, 6.0

Change-Id: Ic10f1e59fad24bcf5f12a805f7674eb82935e525
Reviewed-on: https://review.typo3.org/17633
Reviewed-by: Jigal van Hemert
Tested-by: Jigal van Hemert