contrib/wix/defines.wxi

py3: catch binascii.Error raised from binascii.unhexlify

Before Python 3, binsacii.unhexlify used to raise TypeError, now it raises
binascii.Error.

<Include>

  <?if $(var.Platform) = "x64" ?>
    <?define IsX64 = yes ?>
  <?else?>
    <?define IsX64 = no ?>
  <?endif?>

</Include>