Fixed: Free animal in player trade.

Player could free an animal already selected in trade.
When abort, client was given a copy of the (ghost)item in bag.

--HG--
branch : develop

code/ryzom/client/src/interface_v3/action_handler_game.cpp

@@ -1532,6 +1532,7 @@ public:
 	virtual void execute (CCtrlBase * /* pCaller */, const string &Params)
 	{
 		// free with no confirm
+		if (!UserEntity->isBusy())
 			beastOrder ("free", Params, false);
 	}
 };