app/views/kaminari/ra-twitter-bootstrap/without_count/_prev_page.html.erb
<% if current_page.first? %>
<li class="page-item prev disabled">
<%= link_to raw(t 'admin.pagination.previous'), '#', class: 'page-link' %>
</li>
<% else %>
<li class="page-item prev">
<%= link_to raw(t 'admin.pagination.previous'), url, class: 'page-link' %>
</li>
<% end %>