Revert "Update network.go since To16 converts the IP address ip up to a 16-byte representation. If ip is not an IP address (it is the wrong length), To16 returns nil. (#5134)"

This reverts commit 838578b55f.

weed/util/network.go

@@ -15,13 +15,18 @@ func DetectedHostAddress() string {
 		return ""
 	}
 
-	if v4Address := selectIpV4(netInterfaces); v4Address != "" {
+	if v4Address := selectIpV4(netInterfaces, true); v4Address != "" {
 		return v4Address
 	}
 
+	if v6Address := selectIpV4(netInterfaces, false); v6Address != "" {
+		return v6Address
+	}
+
 	return "localhost"
 }
-func selectIpV4(netInterfaces []net.Interface) string {
+
+func selectIpV4(netInterfaces []net.Interface, isIpV4 bool) string {
 	for _, netInterface := range netInterfaces {
 		if (netInterface.Flags & net.FlagUp) == 0 {
 			continue
@@ -33,9 +38,15 @@ func selectIpV4(netInterfaces []net.Interface) string {
 
 		for _, a := range addrs {
 			if ipNet, ok := a.(*net.IPNet); ok && !ipNet.IP.IsLoopback() {
+				if isIpV4 {
+					if ipNet.IP.To4() != nil {
+						return ipNet.IP.String()
+					}
+				} else {
 					if ipNet.IP.To16() != nil {
 						return ipNet.IP.String()
 					}
+				}
 			}
 		}
 	}