fix compiler option for msvc
fix compiler option for msvc

d-tk/dtk,rdebroiz/dtk,d-tk/dtk,d-tk/dtk,rdebroiz/dtk,d-tk/dtk,d-tk/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk,d-tk/dtk,NicolasSchnitzler/dtk,NicolasSchnitzler/dtk