enlarge the account wizard slightly to acommadate windows large fonts

no reviewer, just a geometry change

mailnews/base/prefs/resources/content/AccountWizard.xul

@@ -29,7 +29,7 @@ Rights Reserved.
 <window id="account-wizard-dialog" xmlns:html="http://www.w3.org/TR/REC-html40"
     xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
     title="New Messenger Account Wizard"
-    height="350" width="450" class="dialog"
+    height="400" width="500" class="dialog"
     onload="onLoad();">
 
 <html:script src="chrome://global/content/strres.js"/>