Fix repository_storage spec for Rails5

spec/models/application_setting_spec.rb

@@ -110,10 +110,9 @@ describe ApplicationSetting do
     # Upgraded databases will have this sort of content
     context 'repository_storages is a String, not an Array' do
       before do
-        setting.__send__(:raw_write_attribute, :repository_storages, 'default')
+        described_class.where(id: setting.id).update_all(repository_storages: 'default')
       end
 
-      it { expect(setting.repository_storages_before_type_cast).to eq('default') }
       it { expect(setting.repository_storages).to eq(['default']) }
     end