[Deprecated API] Use new API instead of deprecated

Use gssdp_client_get_host_ip() instead of gupnp_context_get_host_ip()

Signed-off-by: Ludovic Ferrandis <ludovic.ferrandis@intel.com>

Fixes #148.

Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>