Fix no-connect/update bug when building without SSL, reported by Andy Padavan

Andy Padavan of the ASUS RT-N56U custom firmware project reports that
building without HTTPS support prevents Inadyn from actually checking
and updating DNS records.

... bad #ifdef-fu ...

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
Add support for DuckDNS, courtesy of the ASUS RT-N56U custom firmware project

Support for DuckDNS contributed by Andy Padavan of the ASUS RT-N56U
custom firmware project.

Signed-off-by: Andy Padavan <andy.padavan@gmail.com>
Signed-off-by: Joachim Nilsson <troglobit@gmail.com>