message: remove dead code in CMake
diff: @@ -26,15 +26,6 @@ set(CMAKE_LIBRARY_OUTPUT_DIRECTORY
  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY
  "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
  -# To build shared libraries in Windows,
  -# we set CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS to TRUE.
  -# See https://cmake.org/cmake/help/v3.4/variable/
  -# CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS.html
  -# See https://blog.kitware.com/
  -# create-dlls-on-windows-without-declspec-using-new-cmake-export-all-feature/
  -#
  -## set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
  -
  # Disable C and C++ compiler extensions. C/CXX_EXTENSIONS are ON by default to
  # allow the compilers to use extended variants of the C/CXX language. However,
  # this could expose cross-platform bugs in user code or in the headers of
  