checkout/existing_payment/_stripe partial not found

[ollieh-m]

This commit, merged into master, seems to add checkout/existing_payment/_stripe:

5a4fed1

But that commit isn't in v1.2.0, and as a result I don't have a checkout/existing_payment/_stripe partial, which this code tries to load:

<%=
  render(
    partial: "spree/checkout/existing_payment/#{wallet_payment_source.payment_source.payment_method.partial_name}", locals: {wallet_payment_source: wallet_payment_source, default: wallet_payment_source == @default_wallet_payment_source}
    )
%>