e_notice compliance for email_registration

The current form_alter tries to find the right part of the form by checking if the profile module is installed and the $account['names'] is an array. This works fine unless you have a custom module that adds data to the profile page (like I do) and you don't have profile module enabled).

Attached patch just says "hey, if it's an array, modify it, if not, try the other spot." and should be more reliable.