Installing and upgrading help

I mainly followed the below website to perform the upgrade.
https://docs.moodle.org/38/en/Upgrading
Instead of using linux command "cp -pr", I uploaded the plugin codes with WinSCP.
Afterwards, I copied the original config.php back to /var/www/html/moodle.
I used the below security permission:
chown -R root /path/to/moodle 
chmod -R 0755 /path/to/moodle
And also, change the permission of executable files to 0644. Set ACL for user: daemon to have rwx

The config.php is something like the below:
unset($CFG); // Ignore this line
global $CFG; // This is necessary here for PHPUnit execution
$CFG = new stdClass();
$CFG->dbtype = 'mysqli'; // 'pgsql', 'mariadb', 'mysqli', 'sqlsrv' or 'oci'
$CFG->dblibrary = 'native'; // 'native' only at the moment
$CFG->dbhost = 'localhost'; // eg 'localhost' or 'db.isp.com' or IP
$CFG->dbname = 'moodledb'; // database name, eg moodle
$CFG->dbuser = 'xxxxx'; // your database username
$CFG->dbpass = 'yyyyy'; // your database password
$CFG->prefix = 'mdl_'; // prefix to use for all table names
$CFG->dboptions = array(
    'dbpersist' => false,       
    'dbsocket'  => false,     
    'dbport'    => '',       
    'dbhandlesoptions' => false,               
    'dbcollation' => 'utf8mb4_unicode_ci',                              
     );
$CFG->wwwroot = 'https://moodle.xxxx.edu';
$CFG->dataroot = '/var/www/html/moodledata';
The original config.php of our Moodle before upgrade does not include the statement of "CFG->dirroot". However, it has been working fine from time to time.
I wonder if I should add the below statement before performing the Moodle upgrade. I noticed that config-dist.php does not include this statement.
$CFG->dirroot = '/var/www/html/moodle';
Please advise. Thank you very much.