Allowing bootstrap IPs for ControlD sub-domains

So protocol which uses sub-domain like doq/dot could be bootstrap in
case of no DNS available.

config_internal_test.go

@@ -8,19 +8,42 @@ import (
 )
 
 func TestUpstreamConfig_SetupBootstrapIP(t *testing.T) {
-	uc := &UpstreamConfig{
-		Name:     "test",
-		Type:     ResolverTypeDOH,
-		Endpoint: "https://freedns.controld.com/p2",
-		Timeout:  5000,
+	tests := []struct {
+		name string
+		uc   *UpstreamConfig
+	}{
+		{
+			name: "doh/doh3",
+			uc: &UpstreamConfig{
+				Name:     "doh",
+				Type:     ResolverTypeDOH,
+				Endpoint: "https://freedns.controld.com/p2",
+				Timeout:  5000,
+			},
+		},
+		{
+			name: "doq/dot",
+			uc: &UpstreamConfig{
+				Name:     "dot",
+				Type:     ResolverTypeDOT,
+				Endpoint: "p2.freedns.controld.com",
+				Timeout:  5000,
+			},
+		},
 	}
-	uc.Init()
-	uc.SetupBootstrapIP()
-	if len(uc.bootstrapIPs) == 0 {
-		t.Log(defaultNameservers())
-		t.Fatal("could not bootstrap ip without bootstrap DNS")
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			tc.uc.Init()
+			tc.uc.SetupBootstrapIP()
+			if len(tc.uc.bootstrapIPs) == 0 {
+				t.Log(defaultNameservers())
+				t.Fatalf("could not bootstrap ip: %s", tc.uc.String())
+			}
+		})
 	}
-	t.Log(uc)
+
 }
 
 func TestUpstreamConfig_Init(t *testing.T) {