message: fix cmake file
diff: @@ -120,7 +120,7 @@ SET( Boost_USE_STATIC_LIBS ON CACHE STRING "ON or OFF" )
  set(Boost_USE_MULTITHREADED ON CACHE STRING "ON or OFF" )
  if ("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
  - set(DEBUG_FLAG CACHE "d")
  + set(DEBUG_FLAG ON CACHE STRING "d")
  endif()
  IF( WIN32 )
  