[CSGO] fix regression from v1.5 that made B3 never disconnect leaving pl...

...ayers

See http://forum.bigbrotherbot.net/counter-strike-global-offensive/any-way-to-stop-bot-registrations/msg41564/#msg41564


When a player disconnects, two lines are found in the game log : 
```
L 07/19/2013 - 17:18:44: "f00<2008><STEAM_1:0:11111111><TERRORIST>" disconnected (reason "Disconnect by user.")
L 07/19/2013 - 17:18:44: "f00<2008><STEAM_1:0:11111111>" switched from team <TERRORIST> to <Unassigned>
```
when parsing the 2nd line, B3 MUST NOT recreate the client object