fix forms custom translation configuration

ot_templating/Configuration/Form/CustomFormSetup.yaml

@@ -13,9 +13,6 @@ TYPO3:
             Form:
               renderingOptions:
                 translation:
-                  # <!!!> 'translationFile' becomes 'translationFiles' in typo10+
-                  translationFile:
-                    # Default translation file of EXT:form (always needed, but can be remove in typo10+)
-                    10: 'EXT:form/Resources/Private/Language/locallang.xlf'
+                  translationFiles:
                     # Load custom translation file(s)
-                    20: 'EXT:ot_templating/Resources/Private/Language/Form/locallang.xlf'
+                    10: 'EXT:ot_templating/Resources/Private/Language/Form/locallang.xlf'