fix search domains and remove username from magicdns (#1987)

hscontrol/mapper/mapper_test.go

@@ -127,7 +127,10 @@ func TestDNSConfigMapResponse(t *testing.T) {
 			}
 
 			got := generateDNSConfig(
-				&dnsConfigOrig,
+				&types.Config{
+					DNSConfig:             &dnsConfigOrig,
+					DNSUserNameInMagicDNS: true,
+				},
 				baseDomain,
 				nodeInShared1,
 				peersOfNodeInShared1,
@@ -187,9 +190,9 @@ func Test_fullMapResponse(t *testing.T) {
 		UserID:     0,
 		User:       types.User{Name: "mini"},
 		ForcedTags: []string{},
-		AuthKey:     &types.PreAuthKey{},
-		LastSeen:    &lastSeen,
-		Expiry:      &expire,
+		AuthKey:    &types.PreAuthKey{},
+		LastSeen:   &lastSeen,
+		Expiry:     &expire,
 		Hostinfo:   &tailcfg.Hostinfo{},
 		Routes: []types.Route{
 			{