切换为默认的dns解析;增加resolver=system的支持

internal/net/dialer/dialer.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"net"
-	"runtime"
 	"strings"
 	"syscall"
 	"time"
@@ -147,9 +146,9 @@ func (d *Dialer) dialOnce(ctx context.Context, network, addr, ifceName string, i
 		return nil, fmt.Errorf("dial: unsupported network %s", network)
 	}
 	var resolver *net.Resolver
-	if runtime.GOOS != "android" {
-		resolver = &net.Resolver{PreferGo: true}
-	}
+	//if runtime.GOOS != "android" {
+	//	resolver = &net.Resolver{PreferGo: true}
+	//}
 	netd := net.Dialer{
 		Resolver:  resolver,
 		LocalAddr: ifAddr,