[BUGFIX] Prevent reset of user settings in getFromDottedNotation()

Change-Id: Idd9bd02e81ffb5b3ed02f5bf47d6fa3a9be7cdbd
Resolves: #76406
Releases: master, 7.6
Reviewed-on: https://review.typo3.org/48426


Reviewed-by: Markus Blaschke <typo3@schattenjaeger.net>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>