Support miniupnp-2.2.8 (fixes #2071)

Use UPNP_GetValidIGD for getting external IP.

daemon/UPnP.cpp

@@ -115,10 +115,16 @@ namespace transport
 			return;
 		}
 
+#if (MINIUPNPC_API_VERSION >= 18)
+		err = UPNP_GetValidIGD (m_Devlist, &m_upnpUrls, &m_upnpData, m_NetworkAddr, sizeof (m_NetworkAddr),
+					m_externalIPAddress, sizeof (m_externalIPAddress));
+#else
 		err = UPNP_GetValidIGD (m_Devlist, &m_upnpUrls, &m_upnpData, m_NetworkAddr, sizeof (m_NetworkAddr));
+#endif
 		m_upnpUrlsInitialized=err!=0;
 		if (err == UPNP_IGD_VALID_CONNECTED)
 		{
+#if (MINIUPNPC_API_VERSION < 18)
 			err = UPNP_GetExternalIPAddress (m_upnpUrls.controlURL, m_upnpData.first.servicetype, m_externalIPAddress);
 			if(err != UPNPCOMMAND_SUCCESS)
 			{
@@ -126,6 +132,7 @@ namespace transport
 				return;
 			}
 			else
+#endif
 			{
 				LogPrint (eLogError, "UPnP: Found Internet Gateway Device ", m_upnpUrls.controlURL);
 				if (!m_externalIPAddress[0])