try to reduce CPU consumption on Windows

src/mormot.commit.inc

@@ -1 +1 @@
-'2.1.5797'
+'2.1.5798'

src/net/mormot.net.async.pas

@@ -1842,7 +1842,11 @@ procedure TAsyncConnectionsThread.Execute;
           // main thread will just fill pending events from socket polls
           // (no process because a faulty service would delay all reading)
           begin
-            start := 0;
+            {$ifdef OSWINDOWS}
+            start := -1; // ensure never SleepHiRes(0)
+            {$else}
+            start := 0;  // best reactivity
+            {$endif OSWINDOWS}
             while not Terminated do
             begin
               fWaitForReadPending := false;