CLI created apps fail to build because of HostOsVersion not being set

[asklar]

1. Use the CLI to create an app
2. react-native run-windows

F:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Microsoft\VC\v150\Application Type\Windows Store\10.0\Platforms\Win32\PlatformToolsets\v141\Toolset.targets(24,27):

error MSB4086: A numeric comparison was attempted on "$(HostOsVersion)" that evaluates to "" instead of a number, in condition "'$(HostOsVersion)' > '6.1'". [F:\test\poop\node_modules\react-native-windows\Folly\Folly.vcxproj]

This might be related to a recent VS2019 update

[asklar]

Fixed by #3434 since we now don't specify the hardcoded vctargetspath property