index.html.erb in spree_backend-4.8.1

- old
+ new

@@ -1,10 +1,10 @@
 <% content_for :page_title do %>
   <%= Spree.t(:zones) %>
 <% end %>
 
 <% content_for :page_actions do %>
-  <%= button_link_to Spree.t(:new_zone), new_object_url, class: "btn-success", icon: 'add.svg', id: 'admin_new_zone_link' %>
+  <%= button_link_to Spree.t(:new_zone), new_object_url, class: "btn-primary", icon: 'add.svg', id: 'admin_new_zone_link' %>
 <% end if can? :create, Spree::Zone %>
 
 <% if @zones.any? %>
 <div class="table-responsive border rounded bg-white">
   <table class="table" id='listing_zones' data-hook>