mkdist.sh: remove python path for virtualenv

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
Arabic Alef into a

Fix from calibre #1249469
https://github.com/kovidgoyal/calibre/commit/b984f394f90522683232231c18dc961e55406270

Signed-off-by: Hiroshi Miura <miurahr@linux.com>