Do not reuse connection if proxy credentials changed

[peterpiekarski]

Connections are reused even if the user credentials have changed.
This is a security issue. A user could get access to an already existing connection to a server via a proxy even though the user is not allowed to use the proxy for that connection in the first place.

[bagder]

proxy_info_matches() is called for both socks proxies and HTTP(S) proxies, and I'm pretty sure the HTTP(S) case doesn't have this problem (as they are typically authenticated in every request). I suggest you split that into two separate functions so that your improvements only apply for the socks ones.

[peterpiekarski]

Agreed. I split the method into proxy_info_matches (which is now unchanged) and added socks_proxy_info_matches and use it at the right place.

[bagder]

Thanks!