TestApproveAgreement: fix copypasta error for unapprove_agreement_for_countersignature_return_value
TestApproveAgreement: fix copypasta error for unapprove_agreement_for_countersignature_return_value

alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend,alphagov/digitalmarketplace-admin-frontend