xterm color highlight uses black and white

[beewoolie]

Using xterm on Linux and MacOS with TERM=xterm-256color.

 > bat --version
bat 0.24.0

Highlighting the following in a file bat.cc

/** bat.cc

*/

#include "standard.h"

#include "bat.h"

namespace BAT {
  void init () {
    for (int i = 0 ; i < 10 ; ++i)
      ::printf ("%d\n", i);
  }
}

If the terminal has white foreground on black, the line numbers are invisible. If it has black foreground on white, some of the code is invisible.

[keith-hall]

I wonder if this was fixed by #2896