message: core: fix includes
diff: #include <arpa/inet.h>
  #include <errno.h>
  #include <unistd.h> // for close()
  +#else
  #pragma comment(lib, "Ws2_32.lib") // Without this, Ws2_32.lib is not included in static library.
  #endif
  +
  #include <cassert>
  #ifndef WINDOWS
  