<div id="deactivation_stream_modal" class="modal modal-bg hide fade new-style" tabindex="-1" role="dialog" aria-labelledby="deactivation_stream_modal_label" aria-hidden="true">
    <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="{{t 'Close' }}"><span aria-hidden="true">&times;</span></button>
        <h3 id="deactivation_stream_modal_label">{{t "Delete stream" }} <span class="stream_name">{{stream_name}}</span></h3>
    </div>
    <div class="modal-body">
        <p>{{t "Deleting this stream will immediately unsubscribe everyone, and the stream's content will not be recoverable." }} <strong>{{t "Are you sure you want to do this?" }}</strong></p>
    </div>
    <div class="modal-footer">
        <button class="button rounded" data-dismiss="modal">{{t "Cancel" }}</button>
        <button class="button rounded btn-danger" id="do_deactivate_stream_button" data-stream-id="{{stream_id}}">{{t "Yes, delete this stream" }}</button>
    </div>
</div>

<div id="deactivation_stream_modal" class="modal modal-bg hide fade new-style" tabindex="-1" role="dialog" aria-labelledby="deactivation_stream_modal_label" aria-hidden="true">
    <div class="modal-header">
        <button type="button" class="close close-modal-btn" data-dismiss="modal" aria-label="{{t 'Close' }}"><span aria-hidden="true">&times;</span></button>
        <h3 id="deactivation_stream_modal_label">{{t "Delete stream" }} <span class="stream_name">{{stream_name}}</span></h3>
    </div>
    <div class="modal-body">
        <p>{{t "Deleting this stream will immediately unsubscribe everyone, and the stream's content will not be recoverable." }} <strong>{{t "Are you sure you want to do this?" }}</strong></p>
    </div>
    <div class="modal-footer">
        <button class="button rounded close-modal-btn" data-dismiss="modal">{{t "Cancel" }}</button>
        <button class="button rounded btn-danger" id="do_deactivate_stream_button" data-stream-id="{{stream_id}}">{{t "Yes, delete this stream" }}</button>
    </div>
</div>

Add close-modal-btn class to cancel btn in deactivate stream modal.
stream: Add close-modal-btn class to cancel btn in deactivate stream modal.

This commit adds 'close-modal-btn' class to cancel button and cross icon
in the deactivation stream modal.

This change is a prep commit for enabling background events on
'hidden.bs.modal' event. As we would enable background events in furhter
commit using the 'hidden.bs.modal' event, we would need to remove the
'hide.bs.modal' event of deactivation_stream_modal which removes the
element from DOM.
When we remove this event we would need a e.stopPropagation call to avoid
unexpected closing of stream settings which was not a problem previously
because the element was being removed from DOM before actual closing of
modal.
So instead of adding a different handler, we can use the handler used
for stream privacy modal here by adding this new class.
