update post/pre script to detect systemd and behaviour properly

debian/postinst

@@ -1,11 +1,21 @@
 #!/bin/sh
+[ -z "$(pidof systemd)" ] && \
+  USING_SYSTEMD=false || \
+  USING_SYSTEMD=true
 
 case "$1" in
 configure)
-	# create the rc.d calls for startup/shutdown...
-	update-rc.d xrdp defaults
-	# Crank the engine ;)
-	invoke-rc.d xrdp start
+	if $USING_SYSTEMD
+	then
+		systemctl daemon-reload
+		systemctl enable xrdp
+		systemctl start xrdp
+	else
+		# create the rc.d calls for startup/shutdown...
+		update-rc.d xrdp defaults
+		# Crank the engine ;)
+		invoke-rc.d xrdp start
+	fi
 	;;
 esac
 exit 0

debian/prerm

@@ -1,8 +1,18 @@
 #!/bin/sh
+[ -z "$(pidof systemd)" ] && \
+  USING_SYSTEMD=false || \
+  USING_SYSTEMD=true
+
 case "$1" in
 remove|purge)
-	invoke-rc.d xrdp stop
-	update-rc.d xrdp remove
+	if $USING_SYSTEMD
+	then
+		systemctl stop xrdp
+		systemctl daemon-reload
+	else
+		invoke-rc.d xrdp stop
+		update-rc.d xrdp remove
+	fi
 	;;
 esac
 exit 0