[Fix] Add GitTfs.VS2019 to the cake.build
[Fix] Add GitTfs.VS2019 to the cake.build

In f2f6da15 ("Add support for VS2019", 2020-08-03) the support for VS2019
was added, but it was not added to the cake.build script, meaning that
the VS2019 support isn't build/packaged.

Correct this oversight by adding the GitTfs.Vs2019 to the cake.build file.

git-tfs/git-tfs,PKRoma/git-tfs