Avoid noise from python bytecompile on non-python pkgs (RhBug:539635)

Avoid noise from python bytecompile on non-python pkgs (RhBug:539635)
- If a pattern doesn't match, we'd prefer an empty list instead of
  unexpanded garbage thank you... nullglob shell option is just what the
  doctor ordered but unfortunately its a bash-specific thing. Otoh there
  are number of other bash-specific scripts in rpm so probably not
  much of an issue...