if an ipv4-mapped ipv6 address is detected, the ip is converted
into v4 format because it may actually be one of our remote dns ips.
it was reported that a program called "maven", when getting handed our
fake ips in the remote dns subnet, converts the ip to v6 prior to calling
connect():
[proxychains] Strict chain ... 127.0.0.1:1080 ... ::ffff:224.0.0.1:443
<--socket error or timeout!
fixes#77