[TASK] Fix missing nullable return type

Classes/Controller/JobTeaserController.php

@@ -52,7 +52,7 @@ class JobTeaserController extends ActionController {
 	 * @return void
 	 * @throws \TYPO3\CMS\Extbase\Persistence\Exception\InvalidQueryException
 	 */
-	public function indexAction():  \Psr\Http\Message\ResponseInterface {
+	public function indexAction(): ?\Psr\Http\Message\ResponseInterface {
 		$allowedLocations = [];
 		if ($this->settings['locations'] !== '') {
 			$allowedLocations = GeneralUtility::trimExplode(',', $this->settings['locations']);