Fixed two errors of document translation jobs

Added package gnome-doc-utils to standard packages
which is required by the slicing script for document translation.
Fixed an error in manuals-propose-translation-update job definition.

bug 1187253

Change-Id: Ib8c3e950de29f6afbbfad6a1b31bc3cf7c48a52f
Reviewed-on: https://review.openstack.org/32824
Reviewed-by: Khai Do <zaro0508@gmail.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins