bundle libebook

Change-Id: I05d96875b9d1deb87dadd63f446080a6fe3494a9
Reviewed-on: https://gerrit.libreoffice.org/6630
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>