[BitPay] properly call `v2_api_token?` on the BitPay module
[BitPay] properly call `v2_api_token?` on the BitPay module

`v2_api_token?` was called directly from the helper whereas it's defined on the surrounding module

razorpay/offsite_payments,activemerchant/offsite_payments,Shopify/offsite_payments,razorpay/offsite_payments,activemerchant/offsite_payments