Disable Connection When Using Proxy in Wifi

We are Having Problems about MITM (man in the middle) , Our App is including some files for users to download but all download links are HTTPS.
Here if Some User use some proxy in iPhone and make some proxy server based on ssl proxy ( like charles or feddles ) He can sniff our HTTPS links and catch the complete link.

I need some way to disable connection for users that use proxy in their wifi.