Work around debhelper bug #989155

On buster/bullseye this bug is unfixed and the service won't be
correctly stopped/restarted if the old package version doesn't
stop the service in prerm.

Author: mutability

debian-bullseye/dump1090-fa.preinst

@@ -0,0 +1,7 @@
+#!/bin/sh
+set -e
+
+# Work around Debian bug #989155
+if [ "$1" = upgrade ] && [ -d /run/systemd/system ] ; then
+	deb-systemd-invoke stop 'dump1090-fa.service' >/dev/null || true
+fi

debian-buster/dump1090-fa.preinst

@@ -0,0 +1,7 @@
+#!/bin/sh
+set -e
+
+# Work around Debian bug #989155
+if [ "$1" = upgrade ] && [ -d /run/systemd/system ] ; then
+	deb-systemd-invoke stop 'dump1090-fa.service' >/dev/null || true
+fi