Comment 0 for bug 1263663

A platform can still have ipv6 disable for example by doing "sudo sysctl -n net.ipv6.conf.all.disable_ipv6=1" but the ipv6 realted test will not be skipped and that is because of the naive way of detecting ipv6 support in the system.

I am proposing in this patch a better way to detect wether ipv6 is enabled or no in a machine.