Fix failing package build on s390x. Closes: #1023788.

This branch has been tested and builds successfully on amd64 and s390x

Relevant links: https://www.qemu.org/docs/master/system/target-s390x.html https://unix.org/version2/whatsnew/lp64_wp.html https://www.debian.org/doc/manuals/maint-guide/update.en.html