iOS 10 "Starting WebFilter logging for process" + Proxy-Authorization header removed from request

Question

Starting from iOS 10 I noticed such logs in my app

yyyy-MM-dd HH:mm:sss HelloWorld[XXX:XXXXXX] WF: === Starting WebFilter logging for process HelloWorld
yyyy-MM-dd HH:mm:sss HelloWorld[XXX:XXXXXX] WF: _userSettingsForUser mobile: {
    filterBlacklist =     (
    );
    filterWhitelist =     (
    );
    restrictWeb = 1;
    useContentFilter = 0;
    useContentFilterOverrides = 0;
    whitelistEnabled = 0;
}
yyyy-MM-dd HH:mm:sss HelloWorld[XXX:XXXXXX] WF: _WebFilterIsActive returning: NO

I have reviewed iOS 10 Release notes but there is no info about WebFilter feature

Also I noticed that for some sites Proxy-Authorization removed from request (I use programmatically configured proxy) and this issue started from iOS 10.

Anybody can throw a light on this?

Update 1

I found stable case when this happens

1. WebView request / for some site example.org over https
2. Received html contains http link to some resource (image for css) like http://example.org/icon.png
3. This lead to Header removal

Answer 1

If you want to remove the message on the XCode’s console then, please find the below steps.

Select Product => Scheme => Edit Scheme or use shortcut : CMD + <
Select the Run option from left side.
On Environment Variables section, add the variable OS_ACTIVITY_MODE = disable