Also update the Windows config to use MSVC2019 instead of 2017
to circumvent the issue that vcpkg is building libraries with the
latest compiler it finds (MSVC 2019), but Qt is building with 2017.
Conflicts:
coin/platform_configs/default.yaml
coin/platform_configs/qt5.yaml
coin/platform_configs/qtsaferenderer.yaml
Change-Id: I88deb114e171046b50fc617ab6bc18b707d61486