Disable the "show threadpool calls active" console command for now.

Whilst this can be very useful to identify threads held too long by incoming packet processing,
it can also be very misleading as the count updates are not atomic (race conditions lead to growth in numbers over time).
This could be solved by making the counts volatile but I don't currently have time to assess the performance impact, though it's almost certainly negligible.
If anybody else wants to do that and re-enable this command then please feel free.

OpenSim/Framework/Servers/ServerBase.cs

@@ -292,11 +292,11 @@ namespace OpenSim.Framework.Servers
                     + "  3 = full stack trace, including common threads\n",
                 HandleDebugThreadpoolLevel);
 
-            m_console.Commands.AddCommand(
-                "Debug", false, "show threadpool calls active",
-                "show threadpool calls active",
-                "Show details about threadpool calls that are still active (currently waiting or in progress)",
-                HandleShowThreadpoolCallsActive);
+//            m_console.Commands.AddCommand(
+//                "Debug", false, "show threadpool calls active",
+//                "show threadpool calls active",
+//                "Show details about threadpool calls that are still active (currently waiting or in progress)",
+//                HandleShowThreadpoolCallsActive);
 
             m_console.Commands.AddCommand(
                 "Debug", false, "show threadpool calls complete",