Fix missing use statements in ext. str. tests

apps/files_external/tests/Controller/UserStoragesControllerTest.php

@@ -23,6 +23,7 @@
 namespace OCA\Files_External\Tests\Controller;
 
 use \OCA\Files_External\Controller\UserStoragesController;
+use OCA\Files_External\Lib\StorageConfig;
 use \OCP\AppFramework\Http;
 use \OCA\Files_External\Service\BackendService;
 

apps/files_external/tests/Service/UserGlobalStoragesServiceTest.php

@@ -22,6 +22,7 @@
  */
 namespace OCA\Files_External\Tests\Service;
 
+use OCA\Files_External\Lib\StorageConfig;
 use OCA\Files_External\NotFoundException;
 use OCA\Files_External\Service\StoragesService;
 use OCA\Files_External\Service\UserGlobalStoragesService;