Authenticator fails to login into the system with disk-full condition

_From @ThomasHabets on October 10, 2014 8:7_

Original [issue 391](https://code.google.com/p/google-authenticator/issues/detail?id=391) created by yurivict on 2014-06-13T22:40:11.000Z:

When the remote host has the disk-full condition, google-authenticator makes it impossible to fix it remotely, because the login always fails with this message in auth.log:
Jun 13 15:30:38 eagle sshd(pam_google_authenticator)[82081]: Failed to update secret file "/home/yuri/.google_authenticator"

This is a very serious problem for an administrator if such situation happens. It locks the remote administrator out.

_Copied from original issue: google/google-authenticator#390_