Fix this warning, there is no need to use an intermediate,
different array pointer.
network.c: In function 'getIPv6Addr':
network.c:50: warning: dereferencing type-punned pointer will break strict-aliasing rules
* src/util/network.c: avoid an intermediary pointer cast
__in6_u.__u6_addr16 is the private name for this struct member,
s6_addr16 is the public one
* src/util/network.c: dont use the private field, but the public one.