Change the symbol that represents debug build
Change the symbol that represents debug build

prev: DEBUG in debug build
now:  NDEBUG in non-debug build

The symbol NDEBUG is identical with it of the function-like macro assert()

Signed-off-by: janus_wel <0d0ff7a9d29f0ddfdd011e7431e322b0a35fda8c@gmail.com>

januswel/cpplib,januswel/cpplib