[BUGFIX] Remove misspelled setting rootlevel for sys_file_collection

The correct setting would have been rootLevel. So it was never
evaluated, remove it.

Resolves: #59773
Releases: 6.3, 6.2, 6.1
Change-Id: I594924caed47c5c911def94524148354790b77b4
Reviewed-on: https://review.typo3.org/31010
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe

typo3/sysext/core/Configuration/TCA/sys_file_collection.php

@@ -13,7 +13,6 @@ return array(
 		'transOrigDiffSourceField' => 'l10n_diffsource',
 		'default_sortby' => 'ORDER BY crdate',
 		'delete' => 'deleted',
-		'rootlevel' => -1,
 		'type' => 'type',
 		'typeicon_column' => 'type',
 		'typeicon_classes' => array(