Fix servername calculation

Fixes #77

Author: szmarczak

source/utils/calculate-server-name.js

@@ -1,5 +1,4 @@
 'use strict';
-const net = require('net');
 /* istanbul ignore file: https://github.com/nodejs/node/blob/v13.0.1/lib/_http_agent.js */
 
 module.exports = options => {
@@ -15,9 +14,8 @@ module.exports = options => {
 		}
 	}
 
-	if (net.isIP(servername)) {
-		return '';
-	}
+	// Removed empty string return for IP,
+	// otherwise https://1.1.1.1/ would fail.
 
 	return servername;
 };

test/auto.js

@@ -54,6 +54,19 @@ test.after('cleanup', async () => {
 	await h2s.close();
 });
 
+test('http2 via ip', async t => {
+	const request = await http2.auto({
+		protocol: 'https:',
+		hostname: '127.0.0.1',
+		port: h2s.address().port
+	});
+	request.end();
+
+	const response = await pEvent(request, 'response');
+	const data = await getStream(response);
+	t.is(data, 'h2');
+});
+
 test('http2', async t => {
 	const request = await http2.auto({
 		protocol: 'https:',