debianutils: upgrade 5.17 -> 5.19

ChangeLog:

5.19:
* update-shells: Avoid duplicate lines when package shells contain both
  aliased and canonical shells.

5.18
* po4a/po/fr.po: Updated french translations for manpages.
* d/control: Bump standards version from 4.6.2 to 4.7.0.
* acinclude.m4: Bump DEBIANUTILS_VERSION from 5.17 to 5.18.

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>