columnstore backup / restore do not need root for non root deployment

If i remove the root user check from columnstoreBackup and run it against a non root install it works fine.

[mysql@ip-172-31-17-173 backuprestore]$ ./columnstoreBackup --user=mysql --install-dir=/home/mysql/mariadb/columnstore -vz 172.31.17.173 /mnt

Requireing root user adds additional setup to copy the mysql key to the root acct (which may not be desirable) plus ensuring authorized hosts are complete (another bug).