Update README.md

Author: clowwindy

utils/README.md

@@ -6,13 +6,4 @@ autoban.py
 
 Automatically ban IPs that try to brute force crack the server.
 
-    python autoban.py < /var/log/shadowsocks.log
-
-Use `-c` to specify with how many failure times it should be considered as an
-attack. Default is 3.
-
-To continue watching for the log file:
-
-    nohup tail -f /var/log/shadowsocks.log | python autoban.py >log 2>log &
-
-Use with caution. Avoid to ban yourself.
+See https://github.com/shadowsocks/shadowsocks/wiki/Ban-Brute-Force-Crackers