message: fix reachability detection logic
diff: @@ -29,17 +29,15 @@ static NetworkReachabilityStatus reachability_status_for_flags(SCNetworkReachabi
  if (!(flags & kSCNetworkReachabilityFlagsReachable))
  return NotReachable;
  - NetworkReachabilityStatus status = NotReachable;
  -
  - if (!(flags & kSCNetworkReachabilityFlagsConnectionRequired)) {
  - status = ReachableViaWiFi;
  + if (flags & kSCNetworkReachabilityFlagsConnectionRequired) {
  + if (!(flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) ||
  + (flags & kSCNetworkReachabilityFlagsInterventionRequired)) {
  + return NotReachable;
  }
  -
  - if ((flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) &&
  - !(flags & kSCNetworkReachabilityFlagsInterventionRequired)) {
  - status = ReachableViaWiFi;
  }
  + NetworkReachabilityStatus status = ReachableViaWiFi;
  +
  #if TARGET_OS_IPHONE
  if (flags & kSCNetworkReachabilityFlagsIsWWAN) {
  status = ReachableViaWWAN;
  