[#320] Installing kanto deb package fails in multi-platform docker bu…

…ild (#321)

Signed-off-by: Dimitar Dimitrov <[email protected]>

build/postinst

@@ -1,3 +1,4 @@
+#!/bin/sh
 # Automatically added by dh_systemd_enable/12.1.1bv2019.0b1
 if [ "$1" = "configure" ] || [ "$1" = "abort-upgrade" ] || [ "$1" = "abort-deconfigure" ] || [ "$1" = "abort-remove" ] ; then
     deb-systemd-invoke restart 'mosquitto.service' >/dev/null || true

build/postrm

@@ -1,3 +1,4 @@
+#!/bin/sh
 # Automatically added by dh_systemd_start/12.1.1bv2019.0b1
 if [ -d /run/systemd/system ]; then
     systemctl --system daemon-reload >/dev/null || true

build/prerm

@@ -1,3 +1,4 @@
+#!/bin/sh
 if [ -d /run/systemd/system ] && [ "$1" = remove ]; then
     deb-systemd-invoke stop 'kanto-update-manager.service' >/dev/null || true
     deb-systemd-invoke stop 'system-metrics.service' >/dev/null || true