Another try at fixing Zabbix agent upgrades

packages/zabbix_agent.xml

@@ -17,11 +17,17 @@
             <exit code="any" />
         </install>
 
-        <upgrade include="remove" />
+        <upgrade cmd='%COMSPEC% /C sc stop "Zabbix Agent"'>
+            <exit code="any" />
+        </upgrade>
+        <upgrade cmd='"%PROGRAMFILES%\Zabbix Agent\zabbix_agentd.exe" -c "%PROGRAMFILES%\Zabbix Agent\zabbix_agentd.conf" --uninstall'>
+            <exit code="1" />
+            <exit code="0" />
+        </upgrade>
+        <upgrade cmd='netsh advfirewall firewall del rule name="Zabbix Agent"' />
         <upgrade include="install" />
 
-        <downgrade include="remove" />
+        <downgrade include="upgrade" />
-        <downgrade include="install" />
 
         <remove cmd='%COMSPEC% /C sc stop "Zabbix Agent"'>
             <exit code="any" />