[BUGFIX] Illegal string offset 'translations' in DatabaseRecordList

The return value of TranslationConfigurationProvider->translationInfo
normally is an array, but it is a string in case of an error.
Move the line below the is_array() check, because it is only needed
inside.

Fixes: #47103
Releases: 6.2, 6.1, 6.0, 4.7, 4.5
Change-Id: Ia781eae987d9295bc2b299f83c087669c96dfd00
Reviewed-on: https://review.typo3.org/21459
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe