quilt: Disable external sendmail for deterministic build

quilt: Disable external sendmail for deterministic build

Otherwise, the build results would be different w/o host's /usr/sbin/sendmail:
1) The /usr/share/quilt/compat/sendmail will be genrated if no
   /usr/sbin/sendmail on host
2) No /usr/share/quilt/compat/sendmail if host's has /usr/sbin/sendmail

Use --without-sendmail to make it always generate /usr/share/quilt/compat/sendmail.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>