Update vc12 settings.props for TFS SDK v2.0

If you are having problems compiling on Windows, please see:
https://github.com/otland/forgottenserver/wiki/Compiling-on-Windows

(At the time of this commit, TFS SDK v2.0 has not been released yet, but
is being worked on. Once it has been released, the link on the Wiki page
will point to it.)