attachment in confirmation mails

Hi guys

When i activate the plugin and enable the payment, you do sent a PDF with the bill in the confirmation mail to the client, so far so good.

But: if a client is choosing any other payment like creditcards, paypal etc., there is still an attachment from your QR Bill plugin in the confirmation mail. It’s a PDF with the file name wc-swiss-qr-bill and only 2 bytes big and its empty. how can i manage getting rid of that attachment?

kind regards
lydia