Remove references to prototype (inexistent in OFN) in model properties

app/models/spree/property.rb

@@ -1,7 +1,5 @@
 module Spree
   class Property < ActiveRecord::Base
-    has_and_belongs_to_many :prototypes, join_table: 'spree_properties_prototypes'
-
     has_many :product_properties, dependent: :destroy
     has_many :products, through: :product_properties
 
@@ -10,12 +8,5 @@ module Spree
     validates :name, :presentation, presence: true
 
     scope :sorted, -> { order(:name) }
-
-    def self.find_all_by_prototype(prototype)
-      id = prototype
-      id = prototype.id if prototype.class == Prototype
-      joins("LEFT JOIN properties_prototypes ON property_id = #{self.table_name}.id").
-        where(prototype_id: id)
-    end
   end
 end