fix compatibility with Python 3.8
fix compatibility with Python 3.8

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