OF-1295 add a note about service to upgrade guide

documentation/docs/upgrade-guide.html

@@ -32,12 +32,12 @@
 <ul>
 <h3>Windows EXE</h3>
     <ol>
-        <li>Stop Openfire.</li>
+        <li>Stop Openfire (when using a service, stop it manually).</li>
         <li>Backup the Openfire installation directory. The default is _C:\Program Files\Openfire_</li>
         <li>Backup the Openfire database. Note that the embedded database is backed up in step 2.</li>
         <li>Run the installer for the new version of Openfire (note that the installer MUST point to the base installation directory of the previous version).</li>
         <li>Complete the installer process.</li>
-        <li>Start Openfire.</li>
+        <li>Start Openfire (when using a service, start it manually).</li>
     </ol>
 
 <h3>RPM - RedHat based unix systems (RHEL, CentOS, Fedora, etc)</h3>
@@ -102,4 +102,4 @@ for these special occasions:
 </div>
 
 </body>
-</html>
\ No newline at end of file
+</html>