Tests: Fix CPackComponents NSIS install root
Without CPACK_VERBATIM_VARIABLES
a path with backslashes does not make it through CPackConfig.cmake
properly. Just use forward slashes which NSIS seems to understand anyway.
Without CPACK_VERBATIM_VARIABLES
a path with backslashes does not make it through CPackConfig.cmake
properly. Just use forward slashes which NSIS seems to understand anyway.