changed config parameter type

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/general_display/trunk@77686 735d13b6-9817-0410-8766-e36946ffe9aa
small change

git-svn-id: https://svn.typo3.org/TYPO3v4/Extensions/general_display/trunk@77687 735d13b6-9817-0410-8766-e36946ffe9aa