Fix a typo in events.rst
Fix a typo in events.rst

This PR fixes a tiny typo in the documentation.
vhaupert/mitmproxy,ujjwal96/mitmproxy,cortesi/mitmproxy,cortesi/mitmproxy,vhaupert/mitmproxy,mhils/mitmproxy,ujjwal96/mitmproxy,mhils/mitmproxy,mitmproxy/mitmproxy,zlorb/mitmproxy,Kriechi/mitmproxy,mitmproxy/mitmproxy,Kriechi/mitmproxy,vhaupert/mitmproxy,mitmproxy/mitmproxy,Kriechi/mitmproxy,cortesi/mitmproxy,mhils/mitmproxy,vhaupert/mitmproxy,mitmproxy/mitmproxy,mitmproxy/mitmproxy,mhils/mitmproxy,ujjwal96/mitmproxy,ujjwal96/mitmproxy,mhils/mitmproxy,Kriechi/mitmproxy,zlorb/mitmproxy,zlorb/mitmproxy,cortesi/mitmproxy,zlorb/mitmproxy