Followup to f5d65e1, missing error string to new error code.

Signed-off-by: Andy Padavan <andy.padavan@gmail.com>
Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
Followup to duckdns.org plugin: support dot in DDNS alias.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>