ratepay: JavaScript error "Uncaught TypeError: Cannot read properties of null (reading 'getValue')" when typing in BIC field

[phoenixdev-kl]

Steps to reproduce:

1. In the payment step select ratepay or ratepay_direct_debit payment
2. Go straight to the BIC input field and enter any character -> developer console will display error "Uncaught TypeError: Cannot read properties of null (reading 'getValue')"

No functionality is blocked by this error though.

IMO the blockPaymentMethodInputs() function is not supposed to be called for the ratepay and ratepay_direct_debit BIC fields as there are no bank code or account number fields to toggle. I'll create a pull request.