zsh: fix 4000-realistic.t / pretend_bsdtar
zsh: fix 4000-realistic.t / pretend_bsdtar

zsh defaults to NO_SH_WORD_SPLIT which breaks pretend_bsdtar
so badly 4000-realistic.t hangs.  this was a bug in the test
(or haveopt?) which should have protected itself better.

roman-neuhauser/haveopt,roman-neuhauser/haveopt,roman-neuhauser/haveopt