Remotely close telnet console. Ref #2330

gns3server/utils/asyncio/telnet_server.py

@@ -212,7 +212,8 @@ class AsyncioTelnetServer:
     @asyncio.coroutine
     def close(self):
         for writer, connection in self._connections.items():
-            connection.close()
+            writer.write_eof()
+            yield from writer.drain()
         
     @asyncio.coroutine
     def client_connected_hook(self):