upnp connection exception

[spooky]

After finishing a game it's extremely hard to join/start another. The client doesn't open the game and no error message is displayed.

Log:

2018-08-08 21:17:15,166 INFO     fa.upnp                        UPnP mapping 2a02:a31a:e13e:a000:8f5:c0b5:3e7d:a1b5:6112
2018-08-08 21:17:15,203 ERROR    fa.upnp                        Exception in UPnP createPortMapping.
Traceback (most recent call last):
  File "src\fa\upnp.py", line 37, in createPortMapping
  File "<COMObject <unknown>>", line 4, in Add
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, None, None, None, 0, -2147220984), None)

Probably related to #978