The script fails when the API replies nochg (ie, it got the same IP)

[marco-brandizi]

As per subject, if you call the script from the same IP that YDNS has registered in its DNS server, the scripts fail, due to the fact that the API output has the format: nochg <IP> and update_ip_address() doesn't parse such output correctly.

Note that this isn't the same case where the script compares the current IP with the value it previously saved on a /tmp/ file. Rather, I'm on the same host (and same IP), but after a reboot, ie, the IP saved on /tmp/* is gone, but the API is queried with that same IP.

I've a fix in my fork and I'll send a PR.