Fix styles loading issue with an Add New Subscriber popup

[mcspronko]

audience.html.twig file contains the following code (note the modal2 id):

<!-- Temporary styles fix for #modal div element -->
<div class="remodal" data-remodal-id="modal2" data-remodal-options="hashTracking: false">
    {% include 'partials/blueprints-new-subscriber.html.twig' with { blueprints: admin.blueprints('pages/admin/new_subscriber'), form_id: 'new-subscriber' } %}
</div>

This code helps to load styles for the main modal when opening an Add New Subscriber popup.

The styles should be fixed and the above code removed.