Allow user admin update without password

app/admin/admin_users.rb

@@ -1,6 +1,13 @@
 ActiveAdmin.register AdminUser do
   permit_params :email, :password, :password_confirmation
 
+  controller do
+    def update_resource(object, attributes)
+      update_method = attributes.first[:password].present? ? :update_attributes : :update_without_password
+      object.send(update_method, *attributes)
+    end
+  end
+
   index do
     selectable_column
     id_column

app/admin/users.rb

@@ -1,6 +1,13 @@
 ActiveAdmin.register User do
   permit_params :name, :email, :password, :password_confirmation, :organisation_id
 
+  controller do
+    def update_resource(object, attributes)
+      update_method = attributes.first[:password].present? ? :update_attributes : :update_without_password
+      object.send(update_method, *attributes)
+    end
+  end
+
   index do
     selectable_column
     id_column