[BUGFIX] Parent language is not applied to new child records

If localizing a parent-child structure, usually the language
of the parent element shall be applied to related child records
as well as new child records.

Due to a missing array segment, the accordant section in the
the InlineElement source code never was processed.

Resolves: #57063
Releases: 6.2, 6.1
Change-Id: I7e563044f9889538f9b8171f71f7685722db8266
Reviewed-on: https://review.typo3.org/30448
Reviewed-by: Markus Klein
Reviewed-by: David Greiner
Reviewed-by: Wouter Wolters
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader