nginx http to https proxy with self-signed certificate

I have an nginx proxy to redirect http requests with a specified port to another https url.

Here is my configuration so far:

server {
   listen 59848;
   location / {
      resolver 8.8.8.8;
      proxy_pass https://example.com$uri$is_args$args;
   }
}

Note that "example.com" is only used for this example and later I will restrict the request to be sent only from localhost.

This works just fine, as long as the server behind the "proxy_pass" url uses a valid SSL certificate signed by a well known CA Authority (which root certificate somehow used by nginx).

But I have the problem that I have to use a custom self-signed SSL client Certificate on the nginx-side. Does somebody know how to install this self-signed certificate to nginx?

nginx allows usage of self-signed certificates by default:

Syntax:     proxy_ssl_verify on | off;
Default:    proxy_ssl_verify off;
Context:    stream, server
Enables or disables verification of the proxied server certificate. 

remove the proxy_ssl_verify directive or set it to off.
Read more about it here:
https://www.nginx.com/resources/admin-guide/nginx-tcp-ssl-upstreams/
http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_ssl_verify