gupnp: Update to 0.20.14

Update to latest version (required for latest Rygel).

As the unique executable provided by "gupnp-dev" cannot
work without python, switch from RRECOMMENDS to RDEPENDS
for it, and also be more precise in its required modules.

Signed-off-by: Manuel Bachmann <manuel.bachmann@iot.bzh>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>