Failed to change ownership of secret file to helper_owner when running utility as non-root user

[locknut]

When running the utility (as a non-root user) with the -s option and helper_owner is defined in /etc/google-authenticator.conf, I get the following error:

aabdian@trusty:~$ google-authenticator -s ~/.google_authenticator -l aabdian@trusty
<truncated>
Do you want me to update your "/home/aabdian/.google_authenticator" file (y/n) y
<truncated>
Failed to chown /home/aabdian/.google_authenticator as googleauth: Operation not permitted

Settings in /etc/google-authenticator.conf are:

aabdian@trusty:~$ egrep -v '^$|^#' /etc/google-authenticator.conf
secret=/etc/google-authenticator/${USER}.secret
use_helper=/usr/sbin/gauth_chktoken
helper_owner=googleauth
time-based
disallow-reuse
label=trusty
qr-mode=ANSI
aabdian@trusty:~$

I think the solution here is to simply not attempt to change the ownership of the secret file if the utility is being run as a non-root user.