small fix for adding index on correct templated table/column instead …

…of static users table

generators/authenticated/templates/migration.rb

@@ -17,7 +17,7 @@ def self.up
       t.column :state,                     :string, :null => :no, :default => 'passive'
       t.column :deleted_at,                :datetime<% end %>
     end
-    add_index :users, :login, :unique => true
+    add_index :<%= table_name %>, :login, :unique => true
   end
 
   def self.down