[dns] fix forward mode
[dns] fix forward mode

mhils/mitmproxy,mhils/mitmproxy,mhils/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,mitmproxy/mitmproxy,mitmproxy/mitmproxy,mitmproxy/mitmproxy