[olsrd] added bind v6 only patch

jsoninfo/textinfo: only listen on IPv6 when running under IPv6

When the IPV6_V6ONLY flag is not set then olsrd running on IPv6
will listen on both IPv6 and IPv4 ports. A subsequent process
running on IPv4 can't listen on the same IPv4 port.

See 01c1ea4 at http://olsr.org/git/?p=olsrd.git