Fixes Bloons Monkey City seeing itself as offline (a regression from 5a7d75cd347369ed14dcccc84e796dda20d77580 "nsiproxy.sys: Implement ipv6_forward_enumerate_all.").
The game checks the connectivity with wininet.InternetGetConnectedState(). That depends on iphlpapi.GetAdaptersAddresses(AF_UNSPEC,...). That GetAdaptersAddresses() currently fails if ipv6 is disabled in Linux (e. g., not compiled in or disabled with ipv6.disable=1 in kernel command line). In general, I'd say this is sort of broken configuration for our purposes. Modern Windows supports some ipv6 stuff (like creating sockets and using them with ipv6 over ipv4) even without ipv6 being configured on interfaces (and so does Wine). Some games depend on ipv6 socket creation to succeed at least. But in this case it is Wine itself demands ipv6 presence while it is not much needed here.
Then, this specific issue might be fixed differently as far as wininet is concerned of course, maybe handling that in iphlpapi and still failing AF_INET6 requests while not failing AF_UNSPEC. But I guess that is not needed and we can just do it simpler by just restoring the previous behaviour if ipv6 routes are de-facto unsupported (also that modern Windows doesn't fail that, unless maybe in some very specific hacked configuration).