I used to login as :ssh root@servip with a password authentication into my centos 6 server.

I am not sure if what I have done has caused this, but while trying to get over my problem of accessing webmin remotely I followed the following tutorial until I reached:

adding auth required pam_google_authenticator.so into /etc/pam.d/sshd. Then by mistake, I have closed the ssh session. When I tried to login in back with the usual password, I get: Permission denied, please try again error. How can I get over this problem?

I don't have a physical access to the server.