make listening -> not listening -> close debugger consistent

When you press F6, if there was a client, the connection was closed but
if there was not yet a client the debugger was closed entirely.

Now when listening just close the listener first and when you really
want to close just press F6 again.

Signed-off-by: BlackEagle <ike.devolder@gmail.com>

Author: BlackIkeEagle

pythonx/vdebug/session.py

@@ -66,11 +66,10 @@ def run(self):
     def stop(self):
         if self.is_connected():
             self.__session.close_connection()
-        elif self.is_open():
+        elif self.is_listening():
             self.stop_listening()
+        elif self.is_open():
             self.__ui.close()
-        elif self.is_listening():
-            self.listener.stop()
         else:
             self.__ui.say("Vdebug is not running")