reduce MIN_CALLBACK_MS guard time. A value too high introduces a extra

throttle and makes more packets to be sent in bursts and not in steady
 state flow.

OpenSim/Region/ClientStack/Linden/UDP/LLUDPClient.cs

@@ -700,7 +700,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         }
 
 
-        const int MIN_CALLBACK_MS = 30;              
+        const int MIN_CALLBACK_MS = 10;              
 
         /// <summary>
         /// Does an early check to see if this queue empty callback is already