Add missed translations (#8959)

utils/file_backend_local.go

@@ -26,7 +26,7 @@ type LocalFileBackend struct {
 func (b *LocalFileBackend) TestConnection() *model.AppError {
 	f := bytes.NewReader([]byte("testingwrite"))
 	if _, err := writeFileLocally(f, filepath.Join(b.directory, TEST_FILE_PATH)); err != nil {
-		return model.NewAppError("TestFileConnection", "Don't have permissions to write to local path specified or other error.", nil, err.Error(), http.StatusInternalServerError)
+		return model.NewAppError("TestFileConnection", "api.file.test_connection.local.connection.app_error", nil, err.Error(), http.StatusInternalServerError)
 	}
 	os.Remove(filepath.Join(b.directory, TEST_FILE_PATH))
 	mlog.Info("Able to write files to local storage.")