Fix CLI install for SQLite (#2648)

One forgotten condition. Related to
https://github.com/FreshRSS/FreshRSS/pull/2646 and
https://github.com/FreshRSS/FreshRSS/pull/2635

cli/do-install.php

@@ -89,7 +89,7 @@ if (function_exists('opcache_reset')) {
 Minz_Configuration::register('system', DATA_PATH . '/config.php', FRESHRSS_PATH . '/config.default.php');
 FreshRSS_Context::$system_conf = Minz_Configuration::get('system');
 
-Minz_Session::_param('currentUser', $config['default_user']);
+Minz_Session::_param('currentUser', '_');	//Default user
 
 $ok = false;
 try {