Do not use dpkg-maintscript-helper to remove /etc/init.d/nut

debian/changelog

@@ -2,7 +2,7 @@ nut (2.6.4-3) UNRELEASED; urgency=low
 
   * debian/rules: Stop the nut-client before nut-server on systems using static
     boot ordering (Closes: #679451)
-  * debian/nut-server.maintscript: Remove /etc/init.d/nut on upgrade
+  * debian/nut-server.postinst: Remove /etc/init.d/nut on upgrade
     (Closes: #677822)
   * Rename nut-server.lintian-overrides to nut-client.lintian-overrides and
     adjust overrides now that ups-monitor is shipped in nut-client package

debian/control

@@ -3,7 +3,7 @@ Section: admin
 Priority: optional
 Maintainer: Arnaud Quette <aquette@debian.org>
 Uploaders: Laurent Bigonville <bigon@debian.org>
-Build-Depends: debhelper (>= 8.1.0~),
+Build-Depends: debhelper (>= 8),
                cdbs (>= 0.4.90~),
                libgd2-xpm-dev | libgd2-noxpm-dev,
                libsnmp-dev | libsnmp9-dev,
@@ -45,7 +45,6 @@ Provides: nut-usb
 Conflicts: nut-hal-drivers, nut-usb (<< 2.1.0-3), nut-dev (<< 2.2.2)
 Replaces: nut (<< 2.6.1-2~)
 Breaks: nut (<< 2.6.1-2~)
-Pre-Depends: ${misc:Pre-Depends}
 Description: network UPS tools - core system
  Network UPS Tools (NUT) is a client/server monitoring system that
  allows computers to share uninterruptible power supply (UPS) and

debian/nut-server.maintscript

@@ -1,3 +0,0 @@
-#Removing obsolete init script.
-#The file is gone in 2.6.3-2 but was not removed on upgrades.
-rm_conffile /etc/init.d/nut 2.6.4-3~

debian/nut-server.postinst

@@ -49,6 +49,11 @@ case "$1" in
       && udevadm trigger --subsystem-match=usb --action=change
 
     # 557178  udevadm trigger --subsystem-match=usb
+
+    if dpkg --compare-versions "$2" le "2.6.4-2~" ; then
+        rm -f /etc/init.d/nut
+        update-rc.d nut remove >/dev/null
+    fi
     ;;
 
   abort-upgrade)