appveyor: use documented cmake -S
appveyor: use documented cmake -S

cmake -H and -B were undocumented
CMake 3.13 introduced official -S to replace undocumented -H
CMake 3.13 started to officially support -B
Later CMake versions may reuse -H as an alias to --help

Appveyor Visual Studio 2015, 2017 and 2019 provide CMake 3.15.5

DaemonEngine/Daemon,DaemonEngine/Daemon,DaemonEngine/Daemon,DaemonEngine/Daemon