Fixes #54 - handles udp socket timeout error

src/util/UpnpPunch.py

@@ -36,12 +36,10 @@ def _m_search_ssdp():
 	sock.settimeout(5)
 
 	try:
-            data = sock.recv(2048)
-        except SocketError:
-            # socket has stopped reading on windows
-            pass
-
-        return data
+		return sock.recv(2048)
+	except socket.error:
+		# no reply from IGD, possibly no IGD on LAN
+		return False
 
 
 def _retrieve_location_from_ssdp(response):
@@ -173,7 +171,12 @@ def open_port(port=15441, desc="UpnpPunch"):
 	Attempt to forward a port using UPnP.
 	"""
 
-	location = _retrieve_location_from_ssdp(_m_search_ssdp())
+	idg_response = _m_search_ssdp()
+
+	if not idg_response:
+		return False
+
+	location = _retrieve_location_from_ssdp(idg_response)
 
 	if not location:
 		return False