From: Mathias Gibbens <mathias@calenhad.com>
Description: Use IP addresses rather than host names so tests will pass in environments where "ip6-localhost" isn't defined (see #1013554)
diff --git a/tcplisten_test.go b/tcplisten_test.go
index e7877d6..f2f04b6 100644
--- a/tcplisten_test.go
+++ b/tcplisten_test.go
@@ -37,8 +37,8 @@ func TestConfigBacklog(t *testing.T) {
 }
 
 func testConfig(t *testing.T, cfg Config) {
-	testConfigV(t, cfg, "tcp4", "localhost:10081")
-	testConfigV(t, cfg, "tcp6", "ip6-localhost:10081")
+	testConfigV(t, cfg, "tcp4", "127.0.0.1:10081")
+	testConfigV(t, cfg, "tcp6", "[::1]:10081")
 }
 
 func testConfigV(t *testing.T, cfg Config, network, addr string) {