Good morning Beatrix,
You should never do it by .htaccess as this will cause an error in the payment gateway.
You must delete the code that you have placed in the .htacess and make the following change:
From the WordPress administration make the following change:
In this way, all customer data will be safe under https in the purchase process and the payment will be correctly validated on the gateway without https without any security level problem.
Cheers
Answered : 02/01/2016 10:34 am