add support for IPv6 transparent mode on Windows
add support for IPv6 transparent mode on Windows

This fixes #3080.

cortesi/mitmproxy,mitmproxy/mitmproxy,cortesi/mitmproxy,mhils/mitmproxy,mhils/mitmproxy,cortesi/mitmproxy,Kriechi/mitmproxy,vhaupert/mitmproxy,ujjwal96/mitmproxy,ujjwal96/mitmproxy,zlorb/mitmproxy,ujjwal96/mitmproxy,Kriechi/mitmproxy,mitmproxy/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,vhaupert/mitmproxy,vhaupert/mitmproxy,mhils/mitmproxy,mhils/mitmproxy,ujjwal96/mitmproxy,Kriechi/mitmproxy,Kriechi/mitmproxy,zlorb/mitmproxy,mitmproxy/mitmproxy,cortesi/mitmproxy,vhaupert/mitmproxy,zlorb/mitmproxy,mitmproxy/mitmproxy,zlorb/mitmproxy