Update SqlRunnerTaskAdditionalFields.php

[woodyc79]

Hello! In TYPO3 v8 i always got an error when adding a scheduler task. Call to undefined method TYPO3\CMS\Fluid\View\StandaloneView::setPartialRootPath()

That's because the method now is called setPartialRootPaths and requires an array. I've changed it already so that it works at least.