Problem: debian/compat 9 but build-dep on 8
Problem: debian/compat 9 but build-dep on 8

Solution: bump build-dep on debhelper to 9

taotetek/zproject,twhittock/zproject,eburkitt/zproject,taotetek/zproject,taotetek/zproject,zeromq/zproject,eburkitt/zproject,hintjens/zproject,paddor/zproject,keent/zproject,zeromq/zproject,hintjens/zproject,paddor/zproject,paddor/zproject,zeromq/zproject,twhittock/zproject,keent/zproject