I've been trying to change the default SSH port on my VM.Standard.E2.1.Micro instance with Ubuntu 20.04 from 22 to 4545. The last time I tried doing this by editing the sshd_config file and changing the port from 22 to 4545, I was locked out for almost a week and had to create another instance just to get things back and running. On an AWS instance, this would have worked. But it seems it's not the same here. So what is the correct procedure to change the SSH port here on OCI?