add prerm to disable runit service

debian/prerm

+#!/bin/sh
+# prerm script for midas
+#
+# see: dh_installdeb(1)
+
+set -e
+
+. /usr/share/debconf/confmodule
+
+# summary of how this script can be called:
+#        * <prerm> `remove'
+#        * <old-prerm> `upgrade' <new-version>
+#        * <new-prerm> `failed-upgrade' <old-version>
+#        * <conflictor's-prerm> `remove' `in-favour' <package> <new-version>
+#        * <deconfigured's-prerm> `deconfigure' `in-favour'
+#          <package-being-installed> <version> `removing'
+#          <conflicting-package> <version>
+# for details, see http://www.debian.org/doc/debian-policy/ or
+# the debian-policy package
+
+case "$1" in
+  remove|upgrade|deconfigure)
+    # Disable runit services.
+    /bin/rm -f /etc/service/radiod 2>/dev/null || true
+    /bin/rm -f /etc/service/redirectord 2>/dev/null || true
+  ;;
+
+  failed-upgrade)
+  ;;
+
+  *)
+    echo "prerm called with unknown argument \`$1'" >&2
+    exit 1
+  ;;
+esac
+
+# dh_installdeb will replace this with shell code automatically
+# generated by other debhelper scripts.
+
+#DEBHELPER#
+
+exit 0
+