Solidus Version: 3.2.5

To Reproduce

1. create a product
2. delete the master price in the default currency (config.currency)
3. attempt creating a new variant
4. see the exception: undefined method 'attributes' for nil:NilClass pointing to

   solidus/backend/app/controllers/spree/admin/variants_controller.rb

   Line 19 in 739b2a6

   @object.prices.build(@object.product.master.default_price.attributes.except("id", "created_at", "updated_at", "deleted_at"))

Current behavior

There's an exception.

Expected behavior

A more friendly behavior is expected.

Screenshots