When killing a zombie session, don't send the stop packet since it often has the effect of killing a newly connected client.

OpenSim/Framework/IClientAPI.cs

@@ -1114,6 +1114,7 @@ namespace OpenSim.Framework
         void InPacket(object NewPack);
         void ProcessInPacket(Packet NewPack);
         void Close();
+        void Close(bool sendStop);
         void Kick(string message);
         
         /// <summary>