Default search setting doesn't work if custom_search module enabled

This is because custom search adds its own submit handler, custom_search_submit() which overrides the redirect set in search_config_form_submit().

These should be added to, not overridden, so moving queues. This is likely to be a non-issue a year latter, but just in case....

I'm taking some liberty but a support request from over a year ago is probably
fixed or irrelevant. If you disagree, please reopen and provide more
details.

15 sec check of the latest 6.x dev version would have confirmed this too :)

$form['#submit'][] = 'custom_search_submit';