Fix issue reported in https://en.delphipraxis.net/topic/12281-python4delphi-crash-immediately-after-launch

Author: pyscripter

Demos/Demo36/ParallelPython.dpr

@@ -109,6 +109,7 @@ begin
       WriteLn('Elapsed ms: ' + SW.ElapsedMilliseconds.ToString);
       WriteLn;
     finally
+      Sleep(1000);  // allow some time for the threads to terminate
       DestroyEngine;
     end;
   except