message: Avoid GNU-related warnings in get_focused_window (lib)
diff: // Copyright 2014 Toggl Desktop developers.
  +// HANDLE_EITNR and scanf("%m") won't work without declaring it a GNU source file
  +#ifndef _GNU_SOURCE
  +#define _GNU_SOURCE
  +#endif
  +#pragma GCC diagnostic ignored "-Wgnu"
  +
  #include <unistd.h>
  #include <fcntl.h>
  #include <stdlib.h>
  