Add error message for forbidden local mount

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

Author: PVince81

apps/files_external/lib/Controller/GlobalStoragesController.php

@@ -103,7 +103,9 @@ public function create(
 		$canCreateNewLocalStorage = $this->config->getSystemValue('files_external_allow_create_new_local', false);
 		if (!$canCreateNewLocalStorage && $backend === 'local') {
 			return new DataResponse(
-				null,
+				[
+					'message' => $this->l10n->t('Forbidden to manage local mounts')
+				],
 				Http::STATUS_FORBIDDEN
 			);
 		}

apps/files_external/lib/Controller/StoragesController.php

@@ -140,7 +140,9 @@ protected function createStorage(
 		$canCreateNewLocalStorage = $this->config->getSystemValue('files_external_allow_create_new_local', false);
 		if (!$canCreateNewLocalStorage && $backend === 'local') {
 			return new DataResponse(
-				null,
+				[
+					'message' => $this->l10n->t('Forbidden to manage local mounts')
+				],
 				Http::STATUS_FORBIDDEN
 			);
 		}

apps/files_external/lib/Controller/UserStoragesController.php

@@ -133,7 +133,9 @@ public function create(
 		$canCreateNewLocalStorage = $this->config->getSystemValue('files_external_allow_create_new_local', false);
 		if (!$canCreateNewLocalStorage && $backend === 'local') {
 			return new DataResponse(
-				null,
+				[
+					'message' => $this->l10n->t('Forbidden to manage local mounts')
+				],
 				Http::STATUS_FORBIDDEN
 			);
 		}