fix issue occuring with set_server

lib/interface.py

@@ -562,6 +562,8 @@ class Interface(threading.Thread):
             self.s.shutdown(socket.SHUT_RDWR)
             self.s.close()
 
+        self.is_connected = False
+
 
     def is_up_to_date(self):
         return self.unanswered_requests == {}

lib/network.py

@@ -232,7 +232,7 @@ class Network(threading.Thread):
 
     def stop_interface(self):
         self.interface.stop() 
-        #self.interface = None
+
 
     def set_server(self, server):
         if self.default_server == server and self.interface.is_connected: