message: Remove redudant compiler flag
  O0 doesn't do optimizations that would remove the frame pointer.
diff: @@ -302,7 +302,7 @@ if(NOT CMAKE_CXX_FLAGS)
  set(CMAKE_CXX_FLAGS "-std=c++11 -Wextra -Wall -pedantic ${EXTRA_FLAGS}")
  endif()
  if(NOT CMAKE_CXX_FLAGS_DEBUG)
  - set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g -fno-omit-frame-pointer")
  + set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
  endif()
  if(NOT CMAKE_CXX_FLAGS_MINSIZEREL)
  set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os")
  