separate multiple plugins with quotes each

envvar: ROUNDCUBEMAIL_PLUGINS=archive,enigma,jqueryui,managesieve,markasjunk,identity_smtp,carddav

resulting config.inc.php included $config['plugins'] = ['archive', 'enigma,jqueryui,managesieve,markasjunk,identity_smtp,carddav'];

now it includes $config['plugins'] = ['archive', 'enigma', 'jqueryui', 'managesieve', 'markasjunk', 'identity_smtp', 'carddav'];