Issue #2540794 by Eli-T, cilefen, karishmaamin, cosmicdreams, yoroy: Configuration synchronization UI does not distinguish between an empty staged configuration, and staged configuration that matches active
(cherry picked from commit 7493e886)
'#empty'=>$this->t('There are no configuration changes to import.'),
'#empty'=>empty($source_list)?$this->t('There is no staged configuration.'):$this->t('The staged configuration is identical to the active configuration.'),