fix for #94067. catch the js exception we get when there is no default account.

this happens the first time you use the account wizard on a new profile.
r/sr=bienvenu

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

@@ -140,7 +140,14 @@ function onLoad() {
     else
         wizardManager.LoadPage("accounttype", false);
     
+    try {
       gDefaultAccount = accountm.defaultAccount;
+    }
+    catch (ex) {
+      // no default account, this is expected the first time you launch mail
+      // on a new profile
+      gDefaultAccount = null;
+    }
 }