point directly to http://www.validome.org/xml/

Thanks to Roman Eisele for mentioning.

i18npool/source/localedata/data/locale.dtd

@@ -22,7 +22,7 @@
     - temporarily (!) change the DOCTYPE of your file to read (all on one line)
       <!DOCTYPE Locale SYSTEM "http://cgit.freedesktop.org/libreoffice/core/plain/i18npool/source/localedata/data/locale.dtd">
 
-    - upload it to the form available at http://www.validome.org/
+    - upload it to the form available at http://www.validome.org/xml/
 
     This will validate the file against the HEAD revision of locale.dtd