fix for #84036. servers that didn't support filters were showing up in the filter dialog.

r=hwaara, sr=bienvenu, a=asa

mailnews/base/search/resources/content/FilterListDialog.xul

@@ -27,7 +27,7 @@ Contributor(s):  H
 
 <!DOCTYPE window SYSTEM "chrome://messenger/locale/FilterListDialog.dtd">
 <window class="dialog" id="filterListDialog"
-  xmlns:NC="http://home.netscape.com/NC-rdf#"
+  xmlns:nc="http://home.netscape.com/NC-rdf#"
   xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
   orient="vertical"
   onload="onLoad();"