Revert "Refresh prepared domain every 30 minutes"

This reverts commit 903352ec9c.

AndroidLibV2rayLite/VPN/vpnservice_support.go

@@ -24,7 +24,6 @@ type resolved struct {
 	domain       string
 	IPs          []net.IP
 	Port         int
-	lastResolved time.Time
 	ipIdx        uint8
 	ipLock       sync.Mutex
 	lastSwitched time.Time
@@ -98,7 +97,7 @@ func (d *ProtectedDialer) PrepareResolveChan() {
 	d.resolveChan = make(chan struct{})
 }
 
-func (d *ProtectedDialer) ResolveChan() chan struct{} {
+func (d *ProtectedDialer) ResolveChan() <-chan struct{} {
 	return d.resolveChan
 }
 
@@ -138,10 +137,9 @@ func (d *ProtectedDialer) lookupAddr(addr string) (*resolved, error) {
 	}
 
 	rs := &resolved{
-		domain:       host,
-		IPs:          IPs,
-		Port:         portnum,
-		lastResolved: time.Now(),
+		domain: host,
+		IPs:    IPs,
+		Port:   portnum,
 	}
 
 	return rs, nil
@@ -152,6 +150,7 @@ func (d *ProtectedDialer) PrepareDomain(domainName string, closeCh <-chan struct
 	log.Printf("Preparing Domain: %s", domainName)
 	d.currentServer = domainName
 
+	defer close(d.resolveChan)
 	maxRetry := 10
 	for {
 		if maxRetry == 0 {
@@ -213,10 +212,6 @@ func (d *ProtectedDialer) Dial(ctx context.Context,
 			}
 		}
 
-		if time.Now().Sub(d.vServer.lastResolved) > time.Minute * 30 {
-			d.PrepareDomain(Address, nil)
-		}
-
 		fd, err := d.getFd(dest.Network)
 		if err != nil {
 			return nil, err