The membership application form that is displayed by the call-to-action on the donation confirmation page is unusable in some cases.

Steps to Reproduce:

• Open the donation form in a browser.
• Make a donation using the direct-debit payment option.
• Click the "Jetzt Mitglied werden" button on the confirmation page.

Actual Results:

• The previously entered address data is not displayed.
• The bank account form section never displays the required fields for IBAN and BIC.

Expected Results:

• The form is populated with address data that was given during the donation process.
• Selecting the (only) payment option "Lastschrift" should display fields for IBAN and BIC.

Remarks:

• The address data is sent by the server, but the client-side code does not apply them to the form fields, likely due to this error message:

jquery.js:3827 Uncaught Error: Initial state contains unknown keys: accountNumber, bankCode
    at t.exports (membership_form_content.js:41)
    at combineReducers.js:120
    at d (createStore.js:165)
    at Object.dispatch (index.js:28)
    at HTMLDocument.<anonymous> (117a7516eb7c9bcf62c94a2ee5ca3c42.membershipForm.js:426)
    at c (jquery.js:3534)
    at u (jquery.js:3602)