Remove unnecessary specification of engine and transport in Python TimeWriter example.
Remove unnecessary specification of engine and transport in Python TimeWriter example.

JasonRuonanWang/ADIOS2,ornladios/ADIOS2,JasonRuonanWang/ADIOS2,JasonRuonanWang/ADIOS2,ornladios/ADIOS2,ornladios/ADIOS2,JasonRuonanWang/ADIOS2,ornladios/ADIOS2,JasonRuonanWang/ADIOS2,ornladios/ADIOS2