Remove trailing spaces at the end of each line in a file

This tutorial introduces how to make Chrome accept self assigned ssl keys for websites: https://www.systutorials.com/50204/making-chrome-accept-self-signed-certificates-on-linux/ However, on iPhone, Chrome blocks me from access sites with self assigned keys. How to make Chrome on iPhone also accept the ssl keys? At the time when I wrote this reply, there is no way to add Certificate Authorities…