Embeds many tracking fails if original value is `nil`

[vanboom]

I have a case where I am loading model attributes from YML and the history tracking of an embedded relation was failing on line 93 of update.rb. The value[0] value is nil.

  original_value = (value[0]).reject { |rel| rel[paranoia_field].present? }
                                   .map { |v_attrs| format_embeds_many_relation(relation, v_attrs) }
          modified_value = value[1].reject { |rel| rel[paranoia_field].present? }
                                   .map { |v_attrs| format_embeds_many_relation(relation, v_attrs) }

proposed fix...

  original_value = (value[0] || []).reject { |rel| rel[paranoia_field].present? }
                                   .map { |v_attrs| format_embeds_many_relation(relation, v_attrs) }
          modified_value = value[1].reject { |rel| rel[paranoia_field].present? }
                                   .map { |v_attrs| format_embeds_many_relation(relation, v_attrs) }